1 # tzdb data for North and Central America and environs
3 # This file is in the public domain, so clarified as of
4 # 2009-05-17 by Arthur David Olson.
6 # also includes Central America and the Caribbean
8 # This file is by no means authoritative; if you think you know better,
9 # go ahead and edit the file (and please send any changes to
10 # tz@iana.org for general use in the future). For more, please see
11 # the file CONTRIBUTING in the tz distribution.
13 # From Paul Eggert (1999-03-22):
14 # A reliable and entertaining source about time zones is
15 # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
17 ###############################################################################
21 # From Paul Eggert (1999-03-31):
22 # Howse writes (pp 121-125) that time zones were invented by
23 # Professor Charles Ferdinand Dowd (1825-1904),
24 # Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
25 # His pamphlet "A System of National Time for Railroads" (1870)
26 # was the result of his proposals at the Convention of Railroad Trunk Lines
27 # in New York City (1869-10). His 1870 proposal was based on Washington, DC,
28 # but in 1872-05 he moved the proposed origin to Greenwich.
30 # From Paul Eggert (2018-03-20):
31 # Dowd's proposal left many details unresolved, such as where to draw
32 # lines between time zones. The key individual who made time zones
33 # work in the US was William Frederick Allen - railway engineer,
34 # managing editor of the Travelers' Guide, and secretary of the
35 # General Time Convention, a railway standardization group. Allen
36 # spent months in dialogs with scientific and railway leaders,
37 # developed a workable plan to institute time zones, and presented it
38 # to the General Time Convention on 1883-04-11, saying that his plan
39 # meant "local time would be practically abolished" - a plus for
40 # railway scheduling. By the next convention on 1883-10-11 nearly all
41 # railroads had agreed and it took effect on 1883-11-18. That Sunday
42 # was called the "day of two noons", as some locations observed noon
43 # twice. Allen witnessed the transition in New York City, writing:
45 # I heard the bells of St. Paul's strike on the old time. Four
46 # minutes later, obedient to the electrical signal from the Naval
47 # Observatory ... the time-ball made its rapid descent, the chimes
48 # of old Trinity rang twelve measured strokes, and local time was
49 # abandoned, probably forever.
51 # Most of the US soon followed suit. See:
52 # Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56.
53 # https://dx.doi.org/10.2307/3105430
55 # From Paul Eggert (2005-04-16):
56 # That 1883 transition occurred at 12:00 new time, not at 12:00 old time.
57 # See p 46 of David Prerau, Seize the daylight, Thunder's Mouth Press (2005).
59 # From Paul Eggert (2006-03-22):
60 # A good source for time zone historical data in the US is
61 # Thomas G. Shanks, The American Atlas (5th edition),
62 # San Diego: ACS Publications, Inc. (1991).
63 # Make sure you have the errata sheet; the book is somewhat useless without it.
64 # It is the source for most of the pre-1991 US entries below.
66 # From Paul Eggert (2001-03-06):
67 # Daylight Saving Time was first suggested as a joke by Benjamin Franklin
68 # in his whimsical essay "An Economical Project for Diminishing the Cost
69 # of Light" published in the Journal de Paris (1784-04-26).
70 # Not everyone is happy with the results:
72 # I don't really care how time is reckoned so long as there is some
73 # agreement about it, but I object to being told that I am saving
74 # daylight when my reason tells me that I am doing nothing of the kind.
75 # I even object to the implication that I am wasting something
76 # valuable if I stay in bed after the sun has risen. As an admirer
77 # of moonlight I resent the bossy insistence of those who want to
78 # reduce my time for enjoying it. At the back of the Daylight Saving
79 # scheme I detect the bony, blue-fingered hand of Puritanism, eager
80 # to push people into bed earlier, and get them up earlier, to make
81 # them healthy, wealthy and wise in spite of themselves.
83 # -- Robertson Davies, The diary of Samuel Marchbanks,
84 # Clarke, Irwin (1947), XIX, Sunday
86 # For more about the first ten years of DST in the United States, see
87 # Robert Garland, Ten years of daylight saving from the Pittsburgh standpoint
88 # (Carnegie Library of Pittsburgh, 1927).
89 # https://web.archive.org/web/20160517155308/http://www.clpgh.org/exhibit/dst.html
91 # Shanks says that DST was called "War Time" in the US in 1918 and 1919.
92 # However, DST was imposed by the Standard Time Act of 1918, which
93 # was the first nationwide legal time standard, and apparently
94 # time was just called "Standard Time" or "Daylight Saving Time".
96 # From Paul Eggert (2019-06-04):
97 # Here is the legal basis for the US federal rules.
98 # * Public Law 65-106 (1918-03-19) implemented standard and daylight saving
99 # time for the first time across the US, springing forward on March's last
100 # Sunday and falling back on October's last Sunday.
101 # https://www.loc.gov/law/help/statutes-at-large/65th-congress/session-2/c65s2ch24.pdf
102 # * Public Law 66-40 (1919-08-20) repealed DST on October 1919's last Sunday.
103 # https://www.loc.gov/law/help/statutes-at-large/66th-congress/session-1/c66s1ch51.pdf
104 # * Public Law 77-403 (1942-01-20) started wartime DST on 1942-02-09.
105 # https://www.loc.gov/law/help/statutes-at-large/77th-congress/session-2/c77s2ch7.pdf
106 # * Public Law 79-187 (1945-09-25) ended wartime DST on 1945-09-30.
107 # https://www.loc.gov/law/help/statutes-at-large/79th-congress/session-1/c79s1ch388.pdf
108 # * Public Law 89-387 (1966-04-13) reinstituted a national standard for DST,
109 # from April's last Sunday to October's last Sunday, effective 1967.
110 # https://www.govinfo.gov/content/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf
111 # * Public Law 93-182 (1973-12-15) moved the 1974 spring-forward to 01-06.
112 # https://www.govinfo.gov/content/pkg/STATUTE-87/pdf/STATUTE-87-Pg707.pdf
113 # * Public Law 93-434 (1974-10-05) moved the 1975 spring-forward to
114 # February's last Sunday.
115 # https://www.govinfo.gov/content/pkg/STATUTE-88/pdf/STATUTE-88-Pg1209.pdf
116 # * Public Law 99-359 (1986-07-08) moved the spring-forward to April's first
118 # https://www.govinfo.gov/content/pkg/STATUTE-100/pdf/STATUTE-100-Pg764.pdf
119 # * Public Law 109-58 (2005-08-08), effective 2007, moved the spring-forward
120 # to March's second Sunday and the fall-back to November's first Sunday.
121 # https://www.govinfo.gov/content/pkg/PLAW-109publ58/pdf/PLAW-109publ58.pdf
122 # All transitions are at 02:00 local time.
124 # From Arthur David Olson:
125 # Before the Uniform Time Act of 1966 took effect in 1967, observance of
126 # Daylight Saving Time in the US was by local option, except during wartime.
128 # From Arthur David Olson (2000-09-25):
129 # Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
130 # In the introduction, Oboler spoke of "Eastern Peace Time."
131 # An AltaVista search turned up:
132 # https://web.archive.org/web/20000926032210/http://rowayton.org/rhs/hstaug45.html
133 # "When the time is announced over the radio now, it is 'Eastern Peace
134 # Time' instead of the old familiar 'Eastern War Time.' Peace is wonderful."
135 # (August 1945) by way of confirmation.
137 # From Paul Eggert (2017-09-23):
138 # This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.
140 # From Joseph Gallant citing
141 # George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
142 # At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
143 # to switch to London for Attlee's address, but the American people
144 # never got to hear his speech live. According to one press account,
145 # CBS' Bob Trout was first to announce the word of Japan's surrender,
146 # but a few seconds later, NBC, ABC and Mutual also flashed the word
147 # of surrender, all of whom interrupting the bells of Big Ben in
148 # London which were to precede Mr. Attlee's speech.
150 # From Paul Eggert (2003-02-09): It was Robert St John, not Bob Trout. From
151 # Myrna Oliver's obituary of St John on page B16 of today's Los Angeles Times:
153 # ... a war-weary U.S. clung to radios, awaiting word of Japan's surrender.
154 # Any announcement from Asia would reach St. John's New York newsroom on a
155 # wire service teletype machine, which had prescribed signals for major news.
156 # Associated Press, for example, would ring five bells before spewing out
157 # typed copy of an important story, and 10 bells for news "of transcendental
160 # On Aug. 14, stalling while talking steadily into the NBC networks' open
161 # microphone, St. John heard five bells and waited only to hear a sixth bell,
162 # before announcing confidently: "Ladies and gentlemen, World War II is over.
163 # The Japanese have agreed to our surrender terms."
165 # He had scored a 20-second scoop on other broadcasters.
167 # From Arthur David Olson (2005-08-22):
168 # Paul has been careful to use the "US" rules only in those locations
169 # that are part of the United States; this reflects the real scope of
170 # U.S. government action. So even though the "US" rules have changed
171 # in the latest release, other countries won't be affected.
173 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
174 Rule US 1918 1919 - Mar lastSun 2:00 1:00 D
175 Rule US 1918 1919 - Oct lastSun 2:00 0 S
176 Rule US 1942 only - Feb 9 2:00 1:00 W # War
177 Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
178 Rule US 1945 only - Sep 30 2:00 0 S
179 Rule US 1967 2006 - Oct lastSun 2:00 0 S
180 Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
181 Rule US 1974 only - Jan 6 2:00 1:00 D
182 Rule US 1975 only - Feb lastSun 2:00 1:00 D
183 Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
184 Rule US 1987 2006 - Apr Sun>=1 2:00 1:00 D
185 Rule US 2007 max - Mar Sun>=8 2:00 1:00 D
186 Rule US 2007 max - Nov Sun>=1 2:00 0 S
188 # From Arthur David Olson, 2005-12-19
189 # We generate the files specified below to guard against old files with
190 # obsolete information being left in the time zone binary directory.
191 # We limit the list to names that have appeared in previous versions of
192 # this time zone package.
193 # We do these as separate Zones rather than as Links to avoid problems if
194 # a particular place changes whether it observes DST.
195 # We put these specifications here in the northamerica file both to
196 # increase the chances that they'll actually get compiled and to
197 # avoid the need to duplicate the US rules in another file.
199 # Zone NAME STDOFF RULES FORMAT [UNTIL]
202 Zone HST -10:00 - HST
203 Zone EST5EDT -5:00 US E%sT
204 Zone CST6CDT -6:00 US C%sT
205 Zone MST7MDT -7:00 US M%sT
206 Zone PST8PDT -8:00 US P%sT
208 # From U. S. Naval Observatory (1989-01-19):
209 # USA EASTERN 5 H BEHIND UTC NEW YORK, WASHINGTON
210 # USA EASTERN 4 H BEHIND UTC APR 3 - OCT 30
211 # USA CENTRAL 6 H BEHIND UTC CHICAGO, HOUSTON
212 # USA CENTRAL 5 H BEHIND UTC APR 3 - OCT 30
213 # USA MOUNTAIN 7 H BEHIND UTC DENVER
214 # USA MOUNTAIN 6 H BEHIND UTC APR 3 - OCT 30
215 # USA PACIFIC 8 H BEHIND UTC L.A., SAN FRANCISCO
216 # USA PACIFIC 7 H BEHIND UTC APR 3 - OCT 30
217 # USA ALASKA STD 9 H BEHIND UTC MOST OF ALASKA (AKST)
218 # USA ALASKA STD 8 H BEHIND UTC APR 3 - OCT 30 (AKDT)
219 # USA ALEUTIAN 10 H BEHIND UTC ISLANDS WEST OF 170W
220 # USA " 9 H BEHIND UTC APR 3 - OCT 30
221 # USA HAWAII 10 H BEHIND UTC
222 # USA BERING 11 H BEHIND UTC SAMOA, MIDWAY
224 # From Arthur David Olson (1989-01-21):
225 # The above dates are for 1988.
226 # Note the "AKST" and "AKDT" abbreviations, the claim that there's
227 # no DST in Samoa, and the claim that there is DST in Alaska and the
230 # From Arthur David Olson (1988-02-13):
231 # Legal standard time zone names, from United States Code (1982 Edition and
232 # Supplement III), Title 15, Chapter 6, Section 260 and forward. First, names
233 # up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
234 # took effect), as explained in sections 263 and 261:
236 # United States standard eastern time
237 # United States standard mountain time
238 # United States standard central time
239 # United States standard Pacific time
241 # United States standard Alaska time
243 # Next, names from 1967-04-01 until 1983-11-30 (the date for
244 # public law 98-181):
245 # Atlantic standard time
246 # eastern standard time
247 # central standard time
248 # mountain standard time
249 # Pacific standard time
250 # Yukon standard time
251 # Alaska-Hawaii standard time
252 # Bering standard time
253 # And after 1983-11-30:
254 # Atlantic standard time
255 # eastern standard time
256 # central standard time
257 # mountain standard time
258 # Pacific standard time
259 # Alaska standard time
260 # Hawaii-Aleutian standard time
261 # Samoa standard time
262 # The law doesn't give abbreviations.
264 # From Paul Eggert (2016-12-19):
265 # Here are URLs for the 1918 and 1966 legislation:
266 # http://uscode.house.gov/statviewer.htm?volume=40&page=451
267 # http://uscode.house.gov/statviewer.htm?volume=80&page=108
268 # Although the 1918 names were officially "United States Standard
269 # Eastern Time" and similarly for "Central", "Mountain", "Pacific",
270 # and "Alaska", in practice "Standard" was placed just before "Time",
271 # as codified in 1966. In practice, Alaska time was abbreviated "AST"
272 # before 1968. Summarizing the 1967 name changes:
273 # 1918 names 1967 names
274 # -08 Standard Pacific Time (PST) Pacific standard time (PST)
275 # -09 (unofficial) Yukon (YST) Yukon standard time (YST)
276 # -10 Standard Alaska Time (AST) Alaska-Hawaii standard time (AHST)
277 # -11 (unofficial) Nome (NST) Bering standard time (BST)
279 # From Paul Eggert (2023-01-23), from a 2001-01-08 heads-up from Rives McDow:
280 # Public law 106-564 (2000-12-23) introduced "Chamorro standard time"
281 # for time in Guam and the Northern Marianas. See the file "australasia".
282 # Also see 15 U.S.C. §263 <https://www.law.cornell.edu/uscode/text/15/263>.
284 # From Paul Eggert (2015-04-17):
285 # HST and HDT are standardized abbreviations for Hawaii-Aleutian
286 # standard and daylight times. See section 9.47 (p 234) of the
287 # U.S. Government Printing Office Style Manual (2008)
288 # https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf
290 # From Arthur David Olson, 2005-08-09
291 # The following was signed into law on 2005-08-08.
293 # H.R. 6, Energy Policy Act of 2005, SEC. 110. DAYLIGHT SAVINGS.
294 # (a) Amendment.--Section 3(a) of the Uniform Time Act of 1966 (15
295 # U.S.C. 260a(a)) is amended--
296 # (1) by striking "first Sunday of April" and inserting "second
297 # Sunday of March"; and
298 # (2) by striking "last Sunday of October" and inserting "first
299 # Sunday of November'.
300 # (b) Effective Date.--Subsection (a) shall take effect 1 year after the
301 # date of enactment of this Act or March 1, 2007, whichever is later.
302 # (c) Report to Congress.--Not later than 9 months after the effective
303 # date stated in subsection (b), the Secretary shall report to Congress
304 # on the impact of this section on energy consumption in the United
306 # (d) Right to Revert.--Congress retains the right to revert the
307 # Daylight Saving Time back to the 2005 time schedules once the
308 # Department study is complete.
310 # US eastern time, represented by New York
312 # Connecticut, Delaware, District of Columbia, most of Florida,
313 # Georgia, southeast Indiana (Dearborn and Ohio counties), eastern Kentucky
314 # (except America/Kentucky/Louisville below), Maine, Maryland, Massachusetts,
315 # New Hampshire, New Jersey, New York, North Carolina, Ohio,
316 # Pennsylvania, Rhode Island, South Carolina, eastern Tennessee,
317 # Vermont, Virginia, West Virginia
319 # From Dave Cantor (2004-11-02):
320 # Early this summer I had the occasion to visit the Mount Washington
321 # Observatory weather station atop (of course!) Mount Washington [, NH]....
322 # One of the staff members said that the station was on Eastern Standard Time
323 # and didn't change their clocks for Daylight Saving ... so that their
324 # reports will always have times which are 5 hours behind UTC.
326 # From Paul Eggert (2005-08-26):
327 # According to today's Huntsville Times
328 # http://www.al.com/news/huntsvilletimes/index.ssf?/base/news/1125047783228320.xml&coll=1
329 # a few towns on Alabama's "eastern border with Georgia, such as Phenix City
330 # in Russell County, Lanett in Chambers County and some towns in Lee County,
331 # set their watches and clocks on Eastern time." It quotes H.H. "Bubba"
332 # Roberts, city administrator in Phenix City. as saying "We are in the Central
333 # time zone, but we do go by the Eastern time zone because so many people work
336 # From Paul Eggert (2017-02-22):
337 # Four cities are involved. The two not mentioned above are Smiths Station
338 # and Valley. Barbara Brooks, Valley's assistant treasurer, heard it started
339 # because West Point Pepperell textile mills were in Alabama while the
340 # corporate office was in Georgia, and residents voted to keep Eastern
341 # time even after the mills closed. See: Kazek K. Did you know which
342 # Alabama towns are in a different time zone? al.com 2017-02-06.
343 # http://www.al.com/living/index.ssf/2017/02/do_you_know_which_alabama_town.html
345 # From Paul Eggert (2014-09-06):
346 # Monthly Notices of the Royal Astronomical Society 44, 4 (1884-02-08), 208
347 # says that New York City Hall time was 3 minutes 58.4 seconds fast of
348 # Eastern time (i.e., -4:56:01.6) just before the 1883 switch.
350 # Rule NAME FROM TO - IN ON AT SAVE LETTER
351 Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
352 Rule NYC 1920 only - Oct lastSun 2:00 0 S
353 Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
354 Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
355 Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
356 # Zone NAME STDOFF RULES FORMAT [UNTIL]
358 Zone America/New_York -4:56:02 - LMT 1883 Nov 18 17:00u
365 # US central time, represented by Chicago
367 # Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
368 # Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
369 # Washington counties), Illinois, western Indiana
370 # (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
371 # Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
372 # Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
373 # Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
374 # western Tennessee, most of Texas, Wisconsin
376 # From Paul Eggert (2018-01-07):
377 # In 1869 the Chicago Astronomical Society contracted with the city to keep
378 # time. Though delayed by the Great Fire, by 1880 a wire ran from the
379 # Dearborn Observatory (on the University of Chicago campus) to City Hall,
380 # which then sent signals to police and fire stations. However, railroads got
381 # their time signals from the Allegheny Observatory, the Madison Observatory,
382 # the Ann Arbor Observatory, etc., so their clocks did not agree with each
383 # other or with the city's official time. The confusion took some years to
385 # Moser M. How Chicago gave America its time zones. Chicago. 2018-01-04.
386 # http://www.chicagomag.com/city-life/January-2018/How-Chicago-Gave-America-Its-Time-Zones/
388 # From Larry M. Smith (2006-04-26) re Wisconsin:
389 # https://docs.legis.wisconsin.gov/statutes/statutes/175.pdf
390 # is currently enforced at the 01:00 time of change. Because the local
391 # "bar time" in the state corresponds to 02:00, a number of citations
392 # are issued for the "sale of class 'B' alcohol after prohibited
393 # hours" within the deviated hour of this change every year....
395 # From Douglas R. Bomberg (2007-03-12):
396 # Wisconsin has enacted (nearly eleventh-hour) legislation to get WI
397 # Statue 175 closer in synch with the US Congress' intent....
398 # https://docs.legis.wisconsin.gov/2007/related/acts/3
400 # From an email administrator of the City of Fort Pierre, SD (2015-12-21):
401 # Fort Pierre is technically located in the Mountain time zone as is
402 # the rest of Stanley County. Most of Stanley County and Fort Pierre
403 # uses the Central time zone due to doing most of their business in
404 # Pierre so it simplifies schedules. I have lived in Stanley County
405 # all my life and it has been that way since I can remember. (43 years!)
407 # From Paul Eggert (2015-12-25):
408 # Assume this practice predates 1970, so Fort Pierre can use America/Chicago.
410 # From Paul Eggert (2015-04-06):
411 # In 1950s Nashville a public clock had dueling faces, one for conservatives
412 # and the other for liberals; the two sides didn't agree about the time of day.
413 # I haven't found a photo of this clock, nor have I tracked down the TIME
414 # magazine report cited below, but here's the story as told by the late
415 # American journalist John Seigenthaler, who was there:
417 # "The two [newspaper] owners held strongly contrasting political and
418 # ideological views. Evans was a New South liberal, Stahlman an Old South
419 # conservative, and their two papers frequently clashed editorially, often on
420 # the same day.... In the 1950s as the state legislature was grappling with
421 # the question of whether to approve daylight saving time for the entire state,
422 # TIME magazine reported:
424 # "'The Nashville Banner and The Nashville Tennessean rarely agree on anything
425 # but the time of day - and last week they couldn't agree on that.'
427 # "It was all too true. The clock on the front of the building had two faces -
428 # The Tennessean side of the building facing west, the other, east. When it
429 # was high noon Banner time, it was 11 a.m. Tennessean time."
431 # Seigenthaler J. For 100 years, Tennessean had it covered.
432 # The Tennessean 2007-05-11, republished 2015-04-06.
433 # https://www.tennessean.com/story/insider/extras/2015/04/06/archives-seigenthaler-for-100-years-the-tennessean-had-it-covered/25348545/
435 # Rule NAME FROM TO - IN ON AT SAVE LETTER
436 Rule Chicago 1920 only - Jun 13 2:00 1:00 D
437 Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
438 Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
439 Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
440 Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
441 Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
442 # Zone NAME STDOFF RULES FORMAT [UNTIL]
443 Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 18:00u
445 -6:00 Chicago C%sT 1936 Mar 1 2:00
446 -5:00 - EST 1936 Nov 15 2:00
447 -6:00 Chicago C%sT 1942
449 -6:00 Chicago C%sT 1967
451 # Oliver County, ND switched from mountain to central time on 1992-10-25.
452 Zone America/North_Dakota/Center -6:45:12 - LMT 1883 Nov 18 19:00u
453 -7:00 US M%sT 1992 Oct 25 2:00
455 # Morton County, ND, switched from mountain to central time on
456 # 2003-10-26, except for the area around Mandan which was already central time.
457 # See <http://dmses.dot.gov/docimages/p63/135818.pdf>.
458 # Officially this switch also included part of Sioux County, and
459 # Jones, Mellette, and Todd Counties in South Dakota;
460 # but in practice these other counties were already observing central time.
461 # See <http://www.epa.gov/fedrgstr/EPA-IMPACT/2003/October/Day-28/i27056.htm>.
462 Zone America/North_Dakota/New_Salem -6:45:39 - LMT 1883 Nov 18 19:00u
463 -7:00 US M%sT 2003 Oct 26 2:00
466 # From Josh Findley (2011-01-21):
467 # ...it appears that Mercer County, North Dakota, changed from the
468 # mountain time zone to the central time zone at the last transition from
469 # daylight-saving to standard time (on Nov. 7, 2010):
470 # https://www.gpo.gov/fdsys/pkg/FR-2010-09-29/html/2010-24376.htm
471 # http://www.bismarcktribune.com/news/local/article_1eb1b588-c758-11df-b472-001cc4c03286.html
473 # From Andy Lipscomb (2011-01-24):
474 # ...according to the Census Bureau, the largest city is Beulah (although
475 # it's commonly referred to as Beulah-Hazen, with Hazen being the next
476 # largest city in Mercer County). Google Maps places Beulah's city hall
477 # at 47° 15' 51" N, 101° 46' 40" W, which yields an offset of 6h47'07".
479 Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 19:00u
480 -7:00 US M%sT 2010 Nov 7 2:00
483 # US mountain time, represented by Denver
485 # Colorado, far western Kansas, Montana, western
486 # Nebraska, Nevada border (Jackpot, Owyhee, and Mountain City),
487 # New Mexico, southwestern North Dakota,
488 # western South Dakota, far western Texas (El Paso County, Hudspeth County,
489 # and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
491 # From Paul Eggert (2018-10-25):
492 # On 1921-03-04 federal law placed all of Texas into the central time zone.
493 # However, El Paso ignored the law for decades and continued to observe
494 # mountain time, on the grounds that that's what they had always done
495 # and they weren't about to let the federal government tell them what to do.
496 # Eventually the federal government gave in and changed the law on
497 # 1970-04-10 to match what El Paso was actually doing. Although
498 # that's slightly after our 1970 cutoff, there is no need to create a
499 # separate zone for El Paso since they were ignoring the law anyway. See:
500 # Long T. El Pasoans were time rebels, fought to stay in Mountain zone.
501 # El Paso Times. 2018-10-24 06:40 -06.
502 # https://www.elpasotimes.com/story/news/local/el-paso/2018/10/24/el-pasoans-were-time-rebels-fought-stay-mountain-zone/1744509002/
504 # Rule NAME FROM TO - IN ON AT SAVE LETTER
505 Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
506 Rule Denver 1920 only - Oct lastSun 2:00 0 S
507 Rule Denver 1921 only - May 22 2:00 0 S
508 Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
509 Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
510 # Zone NAME STDOFF RULES FORMAT [UNTIL]
511 Zone America/Denver -6:59:56 - LMT 1883 Nov 18 19:00u
513 -7:00 Denver M%sT 1942
515 -7:00 Denver M%sT 1967
518 # US Pacific time, represented by Los Angeles
520 # California, northern Idaho (Benewah, Bonner, Boundary, Clearwater,
521 # Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties, Idaho county
522 # north of the Salmon River, and the towns of Burgdorf and Warren),
523 # Nevada (except West Wendover), Oregon (except the northern ¾ of
524 # Malheur county), and Washington
526 # From Paul Eggert (2016-08-20):
527 # In early February 1948, in response to California's electricity shortage,
528 # PG&E changed power frequency from 60 to 59.5 Hz during daylight hours,
529 # causing electric clocks to lose six minutes per day. (This did not change
530 # legal time, and is not part of the data here.) See:
531 # Ross SA. An energy crisis from the past: Northern California in 1948.
532 # Working Paper No. 8, Institute of Governmental Studies, UC Berkeley,
533 # 1973-11. https://escholarship.org/uc/item/8x22k30c
535 # In another measure to save electricity, DST was instituted from 1948-03-14
536 # at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move
537 # the fallback transition earlier. See pages 3-4 of:
538 # http://clerk.assembly.ca.gov/sites/clerk.assembly.ca.gov/files/archive/Statutes/1948/48Vol1_Chapters.pdf
542 # Governor Warren received a torrent of objecting mail, and it is not too much
543 # to speculate that the objections to Daylight Saving Time were one important
544 # factor in the defeat of the Dewey-Warren Presidential ticket in California.
547 # On December 8 the governor exercised the option, setting the date to January 1
548 # (LA Times 1948-12-09). The transition time was 02:00 (LA Times 1949-01-01).
550 # Despite the controversy, in 1949 California voters approved Proposition 12,
551 # which established DST from April's last Sunday at 01:00 until September's
552 # last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed
553 # the fall-back date to October's last Sunday. See:
554 # https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
555 # https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
557 # Rule NAME FROM TO - IN ON AT SAVE LETTER
558 Rule CA 1948 only - Mar 14 2:01 1:00 D
559 Rule CA 1949 only - Jan 1 2:00 0 S
560 Rule CA 1950 1966 - Apr lastSun 1:00 1:00 D
561 Rule CA 1950 1961 - Sep lastSun 2:00 0 S
562 Rule CA 1962 1966 - Oct lastSun 2:00 0 S
563 # Zone NAME STDOFF RULES FORMAT [UNTIL]
564 Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 20:00u
570 # AK%sT is the modern abbreviation for -09 per USNO.
572 # From Paul Eggert (2017-06-15):
573 # Howse writes that Alaska switched from the Julian to the Gregorian calendar,
574 # and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
575 # On Friday, 1867-10-18 (Gregorian), at precisely 15:30 local time, the
576 # Russian forts and fleet at Sitka fired salutes to mark the ceremony of
577 # formal transfer. See the Sacramento Daily Union (1867-11-14), p 3, col 2.
578 # https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SDU18671114.2.12.1
579 # Sitka workers did not change their calendars until Sunday, 1867-10-20,
580 # and so celebrated two Sundays that week. See: Ahllund T (tr Hallamaa P).
581 # From the memoirs of a Finnish workman. Alaska History. 2006 Fall;21(2):1-25.
582 # http://alaskahistoricalsociety.org/wp-content/uploads/2016/12/Ahllund-2006-Memoirs-of-a-Finnish-Workman.pdf
583 # Include only the time zone part of this transition, ignoring the switch
584 # from Julian to Gregorian, since we can't represent the Julian calendar.
586 # As far as we know, of the locations mentioned below only Sitka was
587 # permanently inhabited in 1867 by anyone using either calendar.
588 # (Yakutat was colonized by the Russians in 1799, but the settlement was
589 # destroyed in 1805 by a Yakutat-kon war party.) Many of Alaska's inhabitants
590 # were unaware of the US acquisition of Alaska, much less of any calendar or
591 # time change. However, the Russian-influenced part of Alaska did observe
592 # Russian time, and it is more accurate to model this than to ignore it.
593 # The database format requires an exact transition time; use the Russian
594 # salute as a somewhat-arbitrary time for the formal transfer of control for
595 # all of Alaska. Sitka's UTC offset is -9:01:13; adjust its 15:30 to the
596 # local times of other Alaskan locations so that they change simultaneously.
598 # From Paul Eggert (2014-07-18):
599 # One opinion of the early 1980s turmoil in Alaska over time zones and
600 # daylight saving time appeared as graffiti on a Juneau airport wall:
601 # "Welcome to Juneau. Please turn your watch back to the 19th century."
602 # See: Turner W. Alaska's four time zones now two. NY Times 1983-11-01.
603 # http://www.nytimes.com/1983/11/01/us/alaska-s-four-time-zones-now-two.html
605 # Steve Ferguson (2011-01-31) referred to the following source:
606 # Norris F. Keeping time in Alaska: national directives, local response.
607 # Alaska History 2001;16(1-2).
608 # http://alaskahistoricalsociety.org/discover-alaska/glimpses-of-the-past/keeping-time-in-alaska/
610 # From Arthur David Olson (2011-02-01):
611 # Here's database-relevant material from the 2001 "Alaska History" article:
613 # On September 20 [1979]...DOT...officials decreed that on April 27,
614 # 1980, Juneau and other nearby communities would move to Yukon Time.
615 # Sitka, Petersburg, Wrangell, and Ketchikan, however, would remain on
618 # ...on September 22, 1980, DOT Secretary Neil E. Goldschmidt rescinded the
619 # Department's September 1979 decision. Juneau and other communities in
620 # northern Southeast reverted to Pacific Time on October 26.
622 # On October 28 [1983]...the Metlakatla Indian Community Council voted
623 # unanimously to keep the reservation on Pacific Time.
625 # According to DOT official Joanne Petrie, Indian reservations are not
626 # bound to follow time zones imposed by neighboring jurisdictions.
628 # (The last is consistent with how the database now handles the Navajo
631 # From Arthur David Olson (2011-02-09):
632 # I just spoke by phone with a staff member at the Metlakatla Indian
633 # Community office (using contact information available at
634 # http://www.commerce.state.ak.us/dca/commdb/CIS.cfm?Comm_Boro_name=Metlakatla
635 # It's shortly after 1:00 here on the east coast of the United States;
636 # the staffer said it was shortly after 10:00 there. When I asked whether
637 # that meant they were on Pacific time, they said no - they were on their
638 # own time. I asked about daylight saving; they said it wasn't used. I
639 # did not inquire about practices in the past.
641 # From Arthur David Olson (2011-08-17):
642 # For lack of better information, assume that Metlakatla's
643 # abandonment of use of daylight saving resulted from the 1983 vote.
645 # From Steffen Thorsen (2015-11-09):
646 # It seems Metlakatla did go off PST on Sunday, November 1, changing
647 # their time to AKST and are going to follow Alaska's DST, switching
648 # between AKST and AKDT from now on....
649 # https://www.krbd.org/2015/10/30/annette-island-times-they-are-a-changing/
651 # From Ryan Stanley (2018-11-06):
652 # The Metlakatla community in Alaska has decided not to change its
653 # clock back an hour starting on November 4th, 2018 (day before yesterday).
654 # They will be gmtoff=-28800 year-round.
655 # https://www.facebook.com/141055983004923/photos/pb.141055983004923.-2207520000.1541465673./569081370202380/
657 # From Paul Eggert (2018-12-16):
658 # In a 2018-12-11 special election, Metlakatla voted to go back to
659 # Alaska time (including daylight saving time) starting next year.
660 # https://www.krbd.org/2018/12/12/metlakatla-to-follow-alaska-standard-time-allow-liquor-sales/
662 # From Ryan Stanley (2019-01-11):
663 # The community will be changing back on the 20th of this month...
664 # From Tim Parenti (2019-01-11):
665 # Per an announcement on the Metlakatla community's official Facebook page, the
666 # "fall back" will be on Sunday 2019-01-20 at 02:00:
667 # https://www.facebook.com/141055983004923/photos/607150969728753/
668 # So they won't be waiting for Alaska to join them on 2019-03-10, but will
669 # rather change their clocks twice in seven weeks.
671 # From Paul Eggert (2023-01-23):
672 # America/Adak is for the Aleutian Islands that are part of Alaska
673 # and are west of 169.5° W.
675 # Zone NAME STDOFF RULES FORMAT [UNTIL]
676 Zone America/Juneau 15:02:19 - LMT 1867 Oct 19 15:33:32
677 -8:57:41 - LMT 1900 Aug 20 12:00
681 -8:00 US P%sT 1980 Apr 27 2:00
682 -9:00 US Y%sT 1980 Oct 26 2:00
683 -8:00 US P%sT 1983 Oct 30 2:00
684 -9:00 US Y%sT 1983 Nov 30
686 Zone America/Sitka 14:58:47 - LMT 1867 Oct 19 15:30
687 -9:01:13 - LMT 1900 Aug 20 12:00
691 -8:00 US P%sT 1983 Oct 30 2:00
692 -9:00 US Y%sT 1983 Nov 30
694 Zone America/Metlakatla 15:13:42 - LMT 1867 Oct 19 15:44:55
695 -8:46:18 - LMT 1900 Aug 20 12:00
699 -8:00 US P%sT 1983 Oct 30 2:00
700 -8:00 - PST 2015 Nov 1 2:00
701 -9:00 US AK%sT 2018 Nov 4 2:00
702 -8:00 - PST 2019 Jan 20 2:00
704 Zone America/Yakutat 14:41:05 - LMT 1867 Oct 19 15:12:18
705 -9:18:55 - LMT 1900 Aug 20 12:00
709 -9:00 US Y%sT 1983 Nov 30
711 Zone America/Anchorage 14:00:24 - LMT 1867 Oct 19 14:31:37
712 -9:59:36 - LMT 1900 Aug 20 12:00
714 -10:00 US A%sT 1967 Apr
716 -10:00 US AH%sT 1983 Oct 30 2:00
717 -9:00 US Y%sT 1983 Nov 30
719 Zone America/Nome 12:58:22 - LMT 1867 Oct 19 13:29:35
720 -11:01:38 - LMT 1900 Aug 20 12:00
723 -11:00 - NST 1967 Apr
725 -11:00 US B%sT 1983 Oct 30 2:00
726 -9:00 US Y%sT 1983 Nov 30
728 Zone America/Adak 12:13:22 - LMT 1867 Oct 19 12:44:35
729 -11:46:38 - LMT 1900 Aug 20 12:00
732 -11:00 - NST 1967 Apr
734 -11:00 US B%sT 1983 Oct 30 2:00
735 -10:00 US AH%sT 1983 Nov 30
737 # The following switches don't make our 1970 cutoff.
739 # Kiska observed Tokyo date and time during Japanese occupation from
740 # 1942-06-06 to 1943-07-29, and similarly for Attu from 1942-06-07 to
741 # 1943-05-29 (all dates American). Both islands are now uninhabited.
743 # Shanks writes that part of southwest Alaska (e.g. Aniak)
744 # switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
745 # and another part (e.g. Akiak) made the same switch five weeks later.
747 # From David Flater (2004-11-09):
748 # In e-mail, 2004-11-02, Ray Hudson, historian/liaison to the Unalaska
749 # Historic Preservation Commission, provided this information, which
750 # suggests that Unalaska deviated from statutory time from early 1967
751 # possibly until 1983:
753 # Minutes of the Unalaska City Council Meeting, January 10, 1967:
754 # "Except for St. Paul and Akutan, Unalaska is the only important
755 # location not on Alaska Standard Time. The following resolution was
756 # made by William Robinson and seconded by Henry Swanson: Be it
757 # resolved that the City of Unalaska hereby goes to Alaska Standard
758 # Time as of midnight Friday, January 13, 1967 (1 A.M. Saturday,
759 # January 14, Alaska Standard Time.) This resolution was passed with
760 # three votes for and one against."
764 # From Arthur David Olson (2010-12-09):
765 # "Hawaiian Time" by Robert C. Schmitt and Doak C. Cox appears on pages 207-225
766 # of volume 26 of The Hawaiian Journal of History (1992). As of 2010-12-09,
767 # the article is available at
768 # https://evols.library.manoa.hawaii.edu/bitstream/10524/239/2/JL26215.pdf
769 # and indicates that standard time was adopted effective noon, January
770 # 13, 1896 (page 218), that in "1933, the Legislature decreed daylight
771 # saving for the period between the last Sunday of each April and the
772 # last Sunday of each September, but less than a month later repealed the
773 # act," (page 220), that year-round daylight saving time was in effect
774 # from 1942-02-09 to 1945-09-30 (page 221, with no time of day given for
775 # when clocks changed) and that clocks were changed by 30 minutes
776 # effective the second Sunday of June, 1947 (page 219, with no time of
777 # day given for when clocks changed). A footnote for the 1933 changes
778 # cites Session Laws of Hawaii 1933, "Act. 90 (approved 26 Apr. 1933)
779 # and Act 163 (approved 21 May 1933)."
781 # From Arthur David Olson (2011-01-19):
782 # The following is from "Laws of the Territory of Hawaii Passed by the
783 # Seventeenth Legislature: Regular Session 1933," available (as of
784 # 2011-01-19) at American University's Pence Law Library. Page 85: "Act
785 # 90...At 2 o'clock ante meridian of the last Sunday in April of each
786 # year, the standard time of this Territory shall be advanced one
787 # hour...This Act shall take effect upon its approval. Approved this 26th
788 # day of April, A. D. 1933. LAWRENCE M JUDD, Governor of the Territory of
789 # Hawaii." Page 172: "Act 163...Act 90 of the Session Laws of 1933 is
790 # hereby repealed...This Act shall take effect upon its approval, upon
791 # which date the standard time of this Territory shall be restored to
792 # that existing immediately prior to the taking effect of said Act 90.
793 # Approved this 21st day of May, A. D. 1933. LAWRENCE M. JUDD, Governor
794 # of the Territory of Hawaii."
796 # Note that 1933-05-21 was a Sunday.
797 # We're left to guess the time of day when Act 163 was approved; guess noon.
799 # Zone NAME STDOFF RULES FORMAT [UNTIL]
800 Zone Pacific/Honolulu -10:31:26 - LMT 1896 Jan 13 12:00
801 -10:30 - HST 1933 Apr 30 2:00
802 -10:30 1:00 HDT 1933 May 21 12:00
803 -10:30 US H%sT 1947 Jun 8 2:00
806 # Now we turn to US areas that have diverged from the consensus since 1970.
808 # Arizona mostly uses MST.
810 # From Paul Eggert (2002-10-20):
812 # The information in the rest of this paragraph is derived from the
813 # Daylight Saving Time web page
814 # <http://www.dlapr.lib.az.us/links/daylight.htm> (2002-01-23)
815 # maintained by the Arizona State Library, Archives and Public Records.
816 # Between 1944-01-01 and 1944-04-01 the State of Arizona used standard
817 # time, but by federal law railroads, airlines, bus lines, military
818 # personnel, and some engaged in interstate commerce continued to
819 # observe war (i.e., daylight saving) time. The 1944-03-17 Phoenix
820 # Gazette says that was the date the law changed, and that 04-01 was
821 # the date the state's clocks would change. In 1945 the State of
822 # Arizona used standard time all year, again with exceptions only as
823 # mandated by federal law. Arizona observed DST in 1967, but Arizona
824 # Laws 1968, ch. 183 (effective 1968-03-21) repealed DST.
826 # Shanks says the 1944 experiment came to an end on 1944-03-17.
827 # Go with the Arizona State Library instead.
829 # Zone NAME STDOFF RULES FORMAT [UNTIL]
830 Zone America/Phoenix -7:28:18 - LMT 1883 Nov 18 19:00u
831 -7:00 US M%sT 1944 Jan 1 0:01
832 -7:00 - MST 1944 Apr 1 0:01
833 -7:00 US M%sT 1944 Oct 1 0:01
835 -7:00 US M%sT 1968 Mar 21
838 # From Arthur David Olson (1988-02-13):
839 # A writer from the Inter Tribal Council of Arizona, Inc.,
840 # notes in private correspondence dated 1987-12-28 that "Presently, only the
841 # Navajo Nation participates in the Daylight Saving Time policy, due to its
842 # large size and location in three states." (The "only" means that other
843 # tribal nations don't use DST.)
845 # From Paul Eggert (2013-08-26):
846 # See America/Denver for a zone appropriate for the Navajo Nation.
848 # Southern Idaho (Ada, Adams, Bannock, Bear Lake, Bingham, Blaine,
849 # Boise, Bonneville, Butte, Camas, Canyon, Caribou, Cassia, Clark,
850 # Custer, Elmore, Franklin, Fremont, Gem, Gooding, Jefferson, Jerome,
851 # Lemhi, Lincoln, Madison, Minidoka, Oneida, Owyhee, Payette, Power,
852 # Teton, Twin Falls, Valley, Washington counties, and the southern
853 # quarter of Idaho county) and eastern Oregon (most of Malheur County)
854 # switched four weeks late in 1974.
856 # Zone NAME STDOFF RULES FORMAT [UNTIL]
857 Zone America/Boise -7:44:49 - LMT 1883 Nov 18 20:00u
858 -8:00 US P%sT 1923 May 13 2:00
860 -7:00 - MST 1974 Feb 3 2:00
865 # For a map of Indiana's time zone regions, see:
866 # https://en.wikipedia.org/wiki/Time_in_Indiana
868 # From Paul Eggert (2018-11-30):
869 # A brief but entertaining history of time in Indiana describes a 1949 debate
870 # in the Indiana House where city legislators (who favored "fast time")
871 # tussled with farm legislators (who didn't) over a bill to outlaw DST:
872 # "Lacking enough votes, the city faction tries to filibuster until time runs
873 # out on the session at midnight, but rural champion Rep. Herbert Copeland,
874 # R-Madison, leans over the gallery railing and forces the official clock
875 # back to 9 p.m., breaking it in the process. The clock sticks on 9 as the
876 # debate rages on into the night. The filibuster finally dies out and the
877 # bill passes, while outside the chamber, clocks read 3:30 a.m. In the end,
878 # it doesn't matter which side won. The law has no enforcement powers and
879 # is simply ignored by fast-time communities."
880 # How Indiana went from 'God's time' to split zones and daylight-saving.
881 # Indianapolis Star. 2018-11-27 14:58 -05.
882 # https://www.indystar.com/story/news/politics/2018/11/27/indianapolis-indiana-time-zone-history-central-eastern-daylight-savings-time/2126300002/
884 # From Paul Eggert (2007-08-17):
885 # Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
886 # with the following exceptions:
888 # - Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
889 # Vanderburgh, and Warrick counties have been like America/Chicago.
891 # - Dearborn and Ohio counties have been like America/New_York.
893 # - Clark, Floyd, and Harrison counties have been like
894 # America/Kentucky/Louisville.
896 # - Crawford, Daviess, Dubois, Knox, Martin, Perry, Pike, Pulaski, Starke,
897 # and Switzerland counties have their own time zone histories as noted below.
899 # Shanks partitioned Indiana into 345 regions, each with its own time history,
900 # and wrote "Even newspaper reports present contradictory information."
901 # Those Hoosiers! Such a flighty and changeable people!
902 # Fortunately, most of the complexity occurred before our cutoff date of 1970.
904 # Other than Indianapolis, the Indiana place names are so nondescript
905 # that they would be ambiguous if we left them at the 'America' level.
906 # So we reluctantly put them all in a subdirectory 'America/Indiana'.
908 # From Paul Eggert (2014-06-26):
909 # https://www.federalregister.gov/articles/2006/01/20/06-563/standard-time-zone-boundary-in-the-state-of-indiana
910 # says "DOT is relocating the time zone boundary in Indiana to move Starke,
911 # Pulaski, Knox, Daviess, Martin, Pike, Dubois, and Perry Counties from the
912 # Eastern Time Zone to the Central Time Zone.... The effective date of
913 # this rule is 2 a.m. EST Sunday, April 2, 2006, which is the
914 # changeover date from standard time to Daylight Saving Time."
915 # Strictly speaking, this meant the affected counties changed their
916 # clocks twice that night, but this obviously was in error. The intent
917 # was that 01:59:59 EST be followed by 02:00:00 CDT.
919 # From Gwillim Law (2007-02-10):
920 # The Associated Press has been reporting that Pulaski County, Indiana is
921 # going to switch from Central to Eastern Time on March 11, 2007....
922 # http://www.indystar.com/apps/pbcs.dll/article?AID=/20070207/LOCAL190108/702070524/0/LOCAL
924 # Rule NAME FROM TO - IN ON AT SAVE LETTER
925 Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
926 Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
927 Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
928 # Zone NAME STDOFF RULES FORMAT [UNTIL]
929 Zone America/Indiana/Indianapolis -5:44:38 - LMT 1883 Nov 18 18:00u
931 -6:00 Indianapolis C%sT 1942
933 -6:00 Indianapolis C%sT 1955 Apr 24 2:00
934 -5:00 - EST 1957 Sep 29 2:00
935 -6:00 - CST 1958 Apr 27 2:00
941 # Eastern Crawford County, Indiana, left its clocks alone in 1974,
942 # as well as from 1976 through 2005.
943 # Rule NAME FROM TO - IN ON AT SAVE LETTER
944 Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
945 Rule Marengo 1951 only - Sep lastSun 2:00 0 S
946 Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
947 Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
948 # Zone NAME STDOFF RULES FORMAT [UNTIL]
949 Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 18:00u
951 -6:00 Marengo C%sT 1961 Apr 30 2:00
953 -5:00 US E%sT 1974 Jan 6 2:00
954 -6:00 1:00 CDT 1974 Oct 27 2:00
959 # Daviess, Dubois, Knox, and Martin Counties, Indiana,
960 # switched from eastern to central time in April 2006, then switched back
962 # Rule NAME FROM TO - IN ON AT SAVE LETTER
963 Rule Vincennes 1946 only - Apr lastSun 2:00 1:00 D
964 Rule Vincennes 1946 only - Sep lastSun 2:00 0 S
965 Rule Vincennes 1953 1954 - Apr lastSun 2:00 1:00 D
966 Rule Vincennes 1953 1959 - Sep lastSun 2:00 0 S
967 Rule Vincennes 1955 only - May 1 0:00 1:00 D
968 Rule Vincennes 1956 1963 - Apr lastSun 2:00 1:00 D
969 Rule Vincennes 1960 only - Oct lastSun 2:00 0 S
970 Rule Vincennes 1961 only - Sep lastSun 2:00 0 S
971 Rule Vincennes 1962 1963 - Oct lastSun 2:00 0 S
972 # Zone NAME STDOFF RULES FORMAT [UNTIL]
973 Zone America/Indiana/Vincennes -5:50:07 - LMT 1883 Nov 18 18:00u
975 -6:00 Vincennes C%sT 1964 Apr 26 2:00
978 -5:00 - EST 2006 Apr 2 2:00
979 -6:00 US C%sT 2007 Nov 4 2:00
982 # Perry County, Indiana, switched from eastern to central time in April 2006.
983 # From Alois Treindl (2019-07-09):
984 # The Indianapolis News, Friday 27 October 1967 states that Perry County
985 # returned to CST. It went again to EST on 27 April 1969, as documented by the
986 # Indianapolis star of Saturday 26 April.
987 # Rule NAME FROM TO - IN ON AT SAVE LETTER
988 Rule Perry 1955 only - May 1 0:00 1:00 D
989 Rule Perry 1955 1960 - Sep lastSun 2:00 0 S
990 Rule Perry 1956 1963 - Apr lastSun 2:00 1:00 D
991 Rule Perry 1961 1963 - Oct lastSun 2:00 0 S
992 # Zone NAME STDOFF RULES FORMAT [UNTIL]
993 Zone America/Indiana/Tell_City -5:47:03 - LMT 1883 Nov 18 18:00u
995 -6:00 Perry C%sT 1964 Apr 26 2:00
996 -5:00 - EST 1967 Oct 29 2:00
997 -6:00 US C%sT 1969 Apr 27 2:00
999 -5:00 - EST 2006 Apr 2 2:00
1002 # Pike County, Indiana moved from central to eastern time in 1977,
1003 # then switched back in 2006, then switched back again in 2007.
1004 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1005 Rule Pike 1955 only - May 1 0:00 1:00 D
1006 Rule Pike 1955 1960 - Sep lastSun 2:00 0 S
1007 Rule Pike 1956 1964 - Apr lastSun 2:00 1:00 D
1008 Rule Pike 1961 1964 - Oct lastSun 2:00 0 S
1009 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1010 Zone America/Indiana/Petersburg -5:49:07 - LMT 1883 Nov 18 18:00u
1012 -6:00 Pike C%sT 1965 Apr 25 2:00
1013 -5:00 - EST 1966 Oct 30 2:00
1014 -6:00 US C%sT 1977 Oct 30 2:00
1015 -5:00 - EST 2006 Apr 2 2:00
1016 -6:00 US C%sT 2007 Nov 4 2:00
1019 # Starke County, Indiana moved from central to eastern time in 1991,
1020 # then switched back in 2006.
1021 # From Arthur David Olson (1991-10-28):
1022 # An article on page A3 of the Sunday, 1991-10-27 Washington Post
1023 # notes that Starke County switched from Central time to Eastern time as of
1025 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1026 Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
1027 Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
1028 Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
1029 Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
1030 Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
1031 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1032 Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 18:00u
1034 -6:00 Starke C%sT 1962 Apr 29 2:00
1035 -5:00 - EST 1963 Oct 27 2:00
1036 -6:00 US C%sT 1991 Oct 27 2:00
1037 -5:00 - EST 2006 Apr 2 2:00
1040 # Pulaski County, Indiana, switched from eastern to central time in
1041 # April 2006 and then switched back in March 2007.
1042 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1043 Rule Pulaski 1946 1960 - Apr lastSun 2:00 1:00 D
1044 Rule Pulaski 1946 1954 - Sep lastSun 2:00 0 S
1045 Rule Pulaski 1955 1956 - Oct lastSun 2:00 0 S
1046 Rule Pulaski 1957 1960 - Sep lastSun 2:00 0 S
1047 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1048 Zone America/Indiana/Winamac -5:46:25 - LMT 1883 Nov 18 18:00u
1050 -6:00 Pulaski C%sT 1961 Apr 30 2:00
1053 -5:00 - EST 2006 Apr 2 2:00
1054 -6:00 US C%sT 2007 Mar 11 2:00
1057 # Switzerland County, Indiana, did not observe DST from 1973 through 2005.
1058 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1059 Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 18:00u
1060 -6:00 US C%sT 1954 Apr 25 2:00
1066 # From Paul Eggert (2018-03-20):
1067 # The Louisville & Nashville Railroad's 1883-11-18 change occurred at
1068 # 10:00 old local time; train were supposed to come to a standstill
1069 # for precisely 18 minutes. See Bartky Fig. 1 (page 50). It is not
1070 # clear how this matched civil time in Louisville, so for now continue
1071 # to assume Louisville switched at noon new local time, like New York.
1073 # From Michael Deckers (2019-08-06):
1074 # From the contemporary source given by Alois Treindl,
1075 # the switch in Louisville on 1946-04-28 was on 00:01
1076 # From Paul Eggert (2019-08-26):
1077 # That source was the Louisville Courier-Journal, 1946-04-27, p 4.
1078 # Shanks gives 02:00 for all 20th-century transition times in Louisville.
1079 # Evidently this is wrong for spring 1946. Although also likely wrong
1080 # for other dates, we have no data.
1082 # Part of Kentucky left its clocks alone in 1974.
1083 # This also includes Clark, Floyd, and Harrison counties in Indiana.
1084 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1085 Rule Louisville 1921 only - May 1 2:00 1:00 D
1086 Rule Louisville 1921 only - Sep 1 2:00 0 S
1087 Rule Louisville 1941 only - Apr lastSun 2:00 1:00 D
1088 Rule Louisville 1941 only - Sep lastSun 2:00 0 S
1089 Rule Louisville 1946 only - Apr lastSun 0:01 1:00 D
1090 Rule Louisville 1946 only - Jun 2 2:00 0 S
1091 Rule Louisville 1950 1961 - Apr lastSun 2:00 1:00 D
1092 Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
1093 Rule Louisville 1956 1961 - Oct lastSun 2:00 0 S
1094 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1095 Zone America/Kentucky/Louisville -5:43:02 - LMT 1883 Nov 18 18:00u
1097 -6:00 Louisville C%sT 1942
1099 -6:00 Louisville C%sT 1961 Jul 23 2:00
1101 -5:00 US E%sT 1974 Jan 6 2:00
1102 -6:00 1:00 CDT 1974 Oct 27 2:00
1105 # Wayne County, Kentucky
1107 # From Lake Cumberland LIFE
1108 # http://www.lake-cumberland.com/life/archive/news990129time.shtml
1109 # (1999-01-29) via WKYM-101.7:
1110 # Clinton County has joined Wayne County in asking the DoT to change from
1111 # the Central to the Eastern time zone.... The Wayne County government made
1112 # the same request in December. And while Russell County officials have not
1113 # taken action, the majority of respondents to a poll conducted there in
1114 # August indicated they would like to change to "fast time" also.
1115 # The three Lake Cumberland counties are the farthest east of any U.S.
1116 # location in the Central time zone.
1118 # From Rich Wales (2000-08-29):
1119 # After prolonged debate, and despite continuing deep differences of opinion,
1120 # Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
1121 # (-0500) time. They won't "fall back" this year. See Sara Shipley,
1122 # The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
1124 # From Paul Eggert (2001-07-16):
1125 # The final rule was published in the
1126 # Federal Register 65, 160 (2000-08-17), pp 50154-50158.
1127 # https://www.gpo.gov/fdsys/pkg/FR-2000-08-17/html/00-20854.htm
1129 Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 18:00u
1132 -6:00 US C%sT 2000 Oct 29 2:00
1136 # From Rives McDow (2000-08-30):
1137 # Here ... are all the changes in the US since 1985.
1138 # Kearny County, KS (put all of county on central;
1139 # previously split between MST and CST) ... 1990-10
1140 # Starke County, IN (from CST to EST) ... 1991-10
1141 # Oliver County, ND (from MST to CST) ... 1992-10
1142 # West Wendover, NV (from PST TO MST) ... 1999-10
1143 # Wayne County, KY (from CST to EST) ... 2000-10
1145 # From Paul Eggert (2001-07-17):
1146 # We don't know where the line used to be within Kearny County, KS,
1147 # so omit that change for now.
1148 # See America/Indiana/Knox for the Starke County, IN change.
1149 # See America/North_Dakota/Center for the Oliver County, ND change.
1150 # West Wendover, NV officially switched from Pacific to mountain time on
1151 # 1999-10-31. See the
1152 # Federal Register 64, 203 (1999-10-21), pp 56705-56707.
1153 # https://www.gpo.gov/fdsys/pkg/FR-1999-10-21/html/99-27240.htm
1154 # However, the Federal Register says that West Wendover already operated
1155 # on mountain time, and the rule merely made this official;
1156 # hence a separate tz entry is not needed.
1160 # From Bob Devine (1988-01-28):
1161 # Michigan didn't observe DST from 1968 to 1973.
1163 # From Paul Eggert (1999-03-31):
1164 # Shanks writes that Michigan started using standard time on 1885-09-18,
1165 # but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
1168 # local time until 1900 when the City Council decreed that clocks should
1169 # be put back twenty-eight minutes to Central Standard Time. Half the
1170 # city obeyed, half refused. After considerable debate, the decision
1171 # was rescinded and the city reverted to Sun time. A derisive offer to
1172 # erect a sundial in front of the city hall was referred to the
1173 # Committee on Sewers. Then, in 1905, Central time was adopted
1176 # This story is too entertaining to be false, so go with Howse over Shanks.
1178 # From Paul Eggert (2001-03-06):
1179 # Garland (1927) writes "Cleveland and Detroit advanced their clocks
1180 # one hour in 1914." This change is not in Shanks. We have no more
1181 # info, so omit this for now.
1183 # From Paul Eggert (2019-07-06):
1184 # Due to a complicated set of legal maneuvers, in 1967 Michigan did
1185 # not start daylight saving time when the rest of the US did.
1186 # Instead, it began DST on Jun 14 at 00:01. This was big news:
1187 # the Detroit Free Press reported it at the top of Page 1 on
1188 # 1967-06-14, in an article "State Adjusting to Switch to Fast Time"
1189 # by Gary Blonston, above an article about Thurgood Marshall's
1190 # confirmation to the US Supreme Court. Although Shanks says Detroit
1191 # observed DST until 1967-10-29 00:01, that time of day seems to be
1192 # incorrect, as the Free Press later said DST ended in Michigan at the
1193 # same time as the rest of the US. Also, although Shanks reports no DST in
1194 # Detroit in 1968, it did observe DST that year; in the November 1968
1195 # election Michigan voters narrowly repealed DST, effective 1969.
1197 # Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
1198 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1199 Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
1200 Rule Detroit 1948 only - Sep lastSun 2:00 0 S
1201 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1202 Zone America/Detroit -5:32:11 - LMT 1905
1203 -6:00 - CST 1915 May 15 2:00
1206 -5:00 Detroit E%sT 1967 Jun 14 0:01
1210 -5:00 - EST 1975 Apr 27 2:00
1213 # Dickinson, Gogebic, Iron, and Menominee Counties, Michigan,
1214 # switched from EST to CST/CDT in 1973.
1215 # Rule NAME FROM TO - IN ON AT SAVE LETTER
1216 Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
1217 Rule Menominee 1946 only - Sep lastSun 2:00 0 S
1218 Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
1219 Rule Menominee 1966 only - Oct lastSun 2:00 0 S
1220 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1221 Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
1223 -6:00 Menominee C%sT 1969 Apr 27 2:00
1224 -5:00 - EST 1973 Apr 29 2:00
1228 # administered by the US Fish and Wildlife Service
1229 # claimed by US under the provisions of the 1856 Guano Islands Act
1230 # also claimed by Haiti
1231 # occupied 1857/1900 by the Navassa Phosphate Co
1232 # US lighthouse 1917/1996-09
1233 # currently uninhabited
1234 # see Mark Fineman, "An Isle Rich in Guano and Discord",
1235 # _Los Angeles Times_ (1998-11-10), A1, A10; it cites
1236 # Jimmy Skaggs, _The Great Guano Rush_ (1994).
1238 ################################################################################
1241 # From Paul Eggert (2017-02-10):
1243 # Unless otherwise specified, the source for data through 1990 is:
1244 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
1245 # San Diego: ACS Publications, Inc. (2003).
1246 # Unfortunately this book contains many errors and cites no sources.
1248 # Many years ago Gwillim Law wrote that a good source
1249 # for time zone data was the International Air Transport
1250 # Association's Standard Schedules Information Manual (IATA SSIM),
1251 # published semiannually. Law sent in several helpful summaries
1252 # of the IATA's data after 1990. Except where otherwise noted,
1253 # IATA SSIM is the source for entries after 1990.
1255 # Other sources occasionally used include:
1257 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
1258 # <https://www.jstor.org/stable/1774359>.
1260 # Pearce C. The Great Daylight Saving Time Controversy.
1261 # Australian Ebook Publisher. 2017. ISBN 978-1-925516-96-8.
1263 # Edward W. Whitman, World Time Differences,
1264 # Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
1265 # which I found in the UCLA library.
1267 # William Willett, The Waste of Daylight, 19th edition
1268 # <http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf>
1271 # See the 'europe' file for Greenland.
1275 # From Alain LaBonté (1994-11-14):
1276 # I post here the time zone abbreviations standardized in Canada
1277 # for both English and French in the CAN/CSA-Z234.4-89 standard....
1279 # UTC Standard time Daylight saving time
1280 # offset French English French English
1284 # -4 HNA AST HAE EDT
1285 # -5 HNE EST HAC CDT
1286 # -6 HNC CST HAR MDT
1287 # -7 HNR MST HAP PDT
1288 # -8 HNP PST HAY YDT
1291 # HN: Heure Normale ST: Standard Time
1292 # HA: Heure Avancée DT: Daylight saving Time
1294 # A: de l'Atlantique Atlantic
1295 # C: du Centre Central
1296 # E: de l'Est Eastern
1299 # P: du Pacifique Pacific
1304 # From Paul Eggert (1994-11-22):
1305 # Alas, this sort of thing must be handled by localization software.
1307 # Unless otherwise specified, the data entries for Canada are all from Shanks
1310 # From Chris Walton (2006-04-01, 2006-04-25, 2006-06-26, 2007-01-31,
1312 # The British Columbia government announced yesterday that it will
1313 # adjust daylight savings next year to align with changes in the
1314 # U.S. and the rest of Canada....
1315 # https://archive.news.gov.bc.ca/releases/news_releases_2005-2009/2006AG0014-000330.htm
1318 # Daylight saving time will be extended by four weeks starting in 2007....
1319 # https://www.novascotia.ca/just/regulations/rg2/2006/ma1206.pdf
1321 # [For New Brunswick] the new legislation dictates that the time change is to
1322 # be done at 02:00 instead of 00:01.
1323 # https://www.gnb.ca/0062/acts/BBA-2006/Chap-19.pdf
1325 # Manitoba has traditionally changed the clock every fall at 03:00.
1326 # As of 2006, the transition is to take place one hour earlier at 02:00.
1327 # https://web2.gov.mb.ca/laws/statutes/ccsm/o030e.php
1329 # [Alberta, Ontario, Quebec] will follow US rules.
1330 # http://www.qp.gov.ab.ca/documents/spring/CH03_06.CFM
1331 # http://www.e-laws.gov.on.ca/DBLaws/Source/Regs/English/2006/R06111_e.htm
1332 # http://www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=5&file=2006C39A.PDF
1334 # P.E.I. will follow US rules....
1335 # http://www.assembly.pe.ca/bills/pdf_chapter/62/3/chapter-41.pdf
1337 # Province of Newfoundland and Labrador....
1338 # http://www.hoa.gov.nl.ca/hoa/bills/Bill0634.htm
1341 # https://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
1343 # N.W.T. will follow US rules. Whoever maintains the government web site
1344 # does not seem to believe in bookmarks. To see the news release, click the
1345 # following link and search for "Daylight Savings Time Change". Press the
1346 # "Daylight Savings Time Change" link; it will fire off a popup using
1348 # http://www.exec.gov.nt.ca/currentnews/currentPR.asp?mode=archive
1351 # An amendment to the Interpretation Act was registered on February 19/2007....
1352 # http://action.attavik.ca/home/justice-gn/attach/2007/gaz02part2.pdf
1354 # From Paul Eggert (2014-10-18):
1355 # H. David Matthews and Mary Vincent's map
1356 # "It's about TIME", _Canadian Geographic_ (September-October 1998)
1357 # http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp
1358 # contains detailed boundaries for regions observing nonstandard
1359 # time and daylight saving time arrangements in Canada circa 1998.
1361 # National Research Council Canada maintains info about time zones and DST.
1362 # https://www.nrc-cnrc.gc.ca/eng/services/time/time_zones.html
1363 # https://www.nrc-cnrc.gc.ca/eng/services/time/faq/index.html#Q5
1364 # Its unofficial information is often taken from Matthews and Vincent.
1366 # From Paul Eggert (2006-06-27):
1367 # For now, assume all of DST-observing Canada will fall into line with the
1370 # From Chris Walton (2011-12-01)
1371 # In the first of Tammy Hardwick's articles
1372 # http://www.ilovecreston.com/?p=articles&t=spec&ar=260
1373 # she quotes the Friday November 1/1918 edition of the Creston Review.
1374 # The quote includes these two statements:
1375 # 'Sunday the CPR went back to the old system of time...'
1376 # '... The daylight saving scheme was dropped all over Canada at the same time,'
1377 # These statements refer to a transition from daylight time to standard time
1378 # that occurred nationally on Sunday October 27/1918. This transition was
1379 # also documented in the Saturday October 26/1918 edition of the Toronto Star.
1381 # In light of that evidence, we alter the date from the earlier believed
1382 # Oct 31, to Oct 27, 1918 (and Sunday is a more likely transition day
1383 # than Thursday) in all Canadian rulesets.
1385 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1386 Rule Canada 1918 only - Apr 14 2:00 1:00 D
1387 Rule Canada 1918 only - Oct 27 2:00 0 S
1388 Rule Canada 1942 only - Feb 9 2:00 1:00 W # War
1389 Rule Canada 1945 only - Aug 14 23:00u 1:00 P # Peace
1390 Rule Canada 1945 only - Sep 30 2:00 0 S
1391 Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
1392 Rule Canada 1974 2006 - Oct lastSun 2:00 0 S
1393 Rule Canada 1987 2006 - Apr Sun>=1 2:00 1:00 D
1394 Rule Canada 2007 max - Mar Sun>=8 2:00 1:00 D
1395 Rule Canada 2007 max - Nov Sun>=1 2:00 0 S
1398 # Newfoundland and Labrador
1400 # From Paul Eggert (2017-10-14):
1401 # Legally Labrador should observe Newfoundland time; see:
1402 # McLeod J. Labrador time - legal or not? St. John's Telegram, 2017-10-07
1403 # http://www.thetelegram.com/news/local/labrador-time--legal-or-not-154860/
1404 # Matthews and Vincent (1998) write that the only part of Labrador
1405 # that follows the rules is the southeast corner, including Port Hope
1406 # Simpson and Mary's Harbour, but excluding, say, Black Tickle.
1408 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1409 Rule StJohns 1917 only - Apr 8 2:00 1:00 D
1410 Rule StJohns 1917 only - Sep 17 2:00 0 S
1411 # Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks & Pottenger.
1412 Rule StJohns 1919 only - May 5 23:00 1:00 D
1413 Rule StJohns 1919 only - Aug 12 23:00 0 S
1414 # For 1931-1935 Whitman gives Apr same date; go with Shanks & Pottenger.
1415 Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
1416 Rule StJohns 1920 1935 - Oct lastSun 23:00 0 S
1417 # For 1936-1941 Whitman gives May Sun>=8 and Oct Sun>=1; go with Shanks &
1419 Rule StJohns 1936 1941 - May Mon>=9 0:00 1:00 D
1420 Rule StJohns 1936 1941 - Oct Mon>=2 0:00 0 S
1421 # Whitman gives the following transitions:
1422 # 1942 03-01/12-31, 1943 05-30/09-05, 1944 07-10/09-02, 1945 01-01/10-07
1423 # but go with Shanks & Pottenger and assume they used Canadian rules.
1424 # For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
1425 # Apr 30 - Sep 24; go with Shanks & Pottenger.
1426 Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
1427 Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
1428 Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
1429 Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
1430 Rule StJohns 1960 1986 - Oct lastSun 2:00 0 S
1431 # From Paul Eggert (2000-10-02):
1432 # INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
1433 # at 00:01 local time. For now, assume it started in 1987.
1435 # From Michael Pelley (2011-09-12):
1436 # We received today, Monday, September 12, 2011, notification that the
1437 # changes to the Newfoundland Standard Time Act have been proclaimed.
1438 # The change in the Act stipulates that the change from Daylight Savings
1439 # Time to Standard Time and from Standard Time to Daylight Savings Time
1440 # now occurs at 2:00AM.
1442 # http://www.assembly.nl.ca/legislation/sr/annualstatutes/2011/1106.chp.htm
1444 # MICHAEL PELLEY | Manager of Enterprise Architecture - Solution Delivery
1445 # Office of the Chief Information Officer
1447 # Government of Newfoundland & Labrador
1449 Rule StJohns 1987 only - Apr Sun>=1 0:01 1:00 D
1450 Rule StJohns 1987 2006 - Oct lastSun 0:01 0 S
1451 Rule StJohns 1988 only - Apr Sun>=1 0:01 2:00 DD
1452 Rule StJohns 1989 2006 - Apr Sun>=1 0:01 1:00 D
1453 Rule StJohns 2007 2011 - Mar Sun>=8 0:01 1:00 D
1454 Rule StJohns 2007 2010 - Nov Sun>=1 0:01 0 S
1456 # St John's has an apostrophe, but Posix file names can't have apostrophes.
1457 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1458 Zone America/St_Johns -3:30:52 - LMT 1884
1459 -3:30:52 StJohns N%sT 1918
1460 -3:30:52 Canada N%sT 1919
1461 -3:30:52 StJohns N%sT 1935 Mar 30
1462 -3:30 StJohns N%sT 1942 May 11
1463 -3:30 Canada N%sT 1946
1464 -3:30 StJohns N%sT 2011 Nov
1467 # most of east Labrador
1469 # The name 'Happy Valley-Goose Bay' is too long; use 'Goose Bay'.
1470 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1471 Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
1473 -3:30:52 Canada N%sT 1919
1474 -3:30:52 - NST 1935 Mar 30
1476 -3:30 StJohns N%sT 1942 May 11
1477 -3:30 Canada N%sT 1946
1478 -3:30 StJohns N%sT 1966 Mar 15 2:00
1479 -4:00 StJohns A%sT 2011 Nov
1483 # west Labrador, Nova Scotia, Prince Edward I,
1484 # Îles-de-la-Madeleine, Listuguj reserve
1486 # From Brian Inglis (2015-07-20):
1487 # From the historical weather station records available at:
1488 # https://weatherspark.com/history/28351/1971/Sydney-Nova-Scotia-Canada
1489 # Sydney shares the same time history as Glace Bay, so was
1490 # likely to be the same across the island....
1491 # Sydney, as the capital and most populous location, or Cape Breton, would
1492 # have been better names for the zone had we known this in 1996.
1494 # From Paul Eggert (2015-07-20):
1495 # Shanks & Pottenger write that since 1970 most of this region has been like
1496 # Halifax. Many locales did not observe peacetime DST until 1972;
1497 # the Cape Breton area, represented by Glace Bay, is the largest we know of
1498 # (Glace Bay was perhaps not the best name choice but no point changing now).
1499 # Shanks & Pottenger also write that Liverpool, NS was the only town
1500 # in Canada to observe DST in 1971 but not 1970; for now we'll assume
1503 # From Jeffery Nichols (2020-01-09):
1504 # America/Halifax ... also applies to Îles-de-la-Madeleine and the Listuguj
1505 # reserve in Quebec. Officially, this came into effect on January 1, 2007
1506 # (Legal Time Act, CQLR c T-5.1), but the legislative debates surrounding that
1507 # bill say that it is "accommodating the customs and practices" of those
1508 # regions, which suggests that they have always been in-line with Halifax.
1510 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1511 Rule Halifax 1916 only - Apr 1 0:00 1:00 D
1512 Rule Halifax 1916 only - Oct 1 0:00 0 S
1513 Rule Halifax 1920 only - May 9 0:00 1:00 D
1514 Rule Halifax 1920 only - Aug 29 0:00 0 S
1515 Rule Halifax 1921 only - May 6 0:00 1:00 D
1516 Rule Halifax 1921 1922 - Sep 5 0:00 0 S
1517 Rule Halifax 1922 only - Apr 30 0:00 1:00 D
1518 Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
1519 Rule Halifax 1923 only - Sep 4 0:00 0 S
1520 Rule Halifax 1924 only - Sep 15 0:00 0 S
1521 Rule Halifax 1925 only - Sep 28 0:00 0 S
1522 Rule Halifax 1926 only - May 16 0:00 1:00 D
1523 Rule Halifax 1926 only - Sep 13 0:00 0 S
1524 Rule Halifax 1927 only - May 1 0:00 1:00 D
1525 Rule Halifax 1927 only - Sep 26 0:00 0 S
1526 Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
1527 Rule Halifax 1928 only - Sep 9 0:00 0 S
1528 Rule Halifax 1929 only - Sep 3 0:00 0 S
1529 Rule Halifax 1930 only - Sep 15 0:00 0 S
1530 Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
1531 Rule Halifax 1932 only - May 1 0:00 1:00 D
1532 Rule Halifax 1933 only - Apr 30 0:00 1:00 D
1533 Rule Halifax 1933 only - Oct 2 0:00 0 S
1534 Rule Halifax 1934 only - May 20 0:00 1:00 D
1535 Rule Halifax 1934 only - Sep 16 0:00 0 S
1536 Rule Halifax 1935 only - Jun 2 0:00 1:00 D
1537 Rule Halifax 1935 only - Sep 30 0:00 0 S
1538 Rule Halifax 1936 only - Jun 1 0:00 1:00 D
1539 Rule Halifax 1936 only - Sep 14 0:00 0 S
1540 Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
1541 Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
1542 Rule Halifax 1939 only - May 28 0:00 1:00 D
1543 Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
1544 Rule Halifax 1946 1949 - Apr lastSun 2:00 1:00 D
1545 Rule Halifax 1946 1949 - Sep lastSun 2:00 0 S
1546 Rule Halifax 1951 1954 - Apr lastSun 2:00 1:00 D
1547 Rule Halifax 1951 1954 - Sep lastSun 2:00 0 S
1548 Rule Halifax 1956 1959 - Apr lastSun 2:00 1:00 D
1549 Rule Halifax 1956 1959 - Sep lastSun 2:00 0 S
1550 Rule Halifax 1962 1973 - Apr lastSun 2:00 1:00 D
1551 Rule Halifax 1962 1973 - Oct lastSun 2:00 0 S
1552 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1553 Zone America/Halifax -4:14:24 - LMT 1902 Jun 15
1554 -4:00 Halifax A%sT 1918
1555 -4:00 Canada A%sT 1919
1556 -4:00 Halifax A%sT 1942 Feb 9 2:00s
1557 -4:00 Canada A%sT 1946
1558 -4:00 Halifax A%sT 1974
1560 Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
1561 -4:00 Canada A%sT 1953
1562 -4:00 Halifax A%sT 1954
1564 -4:00 Halifax A%sT 1974
1569 # From Paul Eggert (2007-01-31):
1570 # The Time Definition Act <http://www.gnb.ca/0062/PDF-acts/t-06.pdf>
1571 # says they changed at 00:01 through 2006, and
1572 # <http://www.canlii.org/nb/laws/sta/t-6/20030127/whole.html> makes it
1573 # clear that this was the case since at least 1993.
1574 # For now, assume it started in 1993.
1576 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1577 Rule Moncton 1933 1935 - Jun Sun>=8 1:00 1:00 D
1578 Rule Moncton 1933 1935 - Sep Sun>=8 1:00 0 S
1579 Rule Moncton 1936 1938 - Jun Sun>=1 1:00 1:00 D
1580 Rule Moncton 1936 1938 - Sep Sun>=1 1:00 0 S
1581 Rule Moncton 1939 only - May 27 1:00 1:00 D
1582 Rule Moncton 1939 1941 - Sep Sat>=21 1:00 0 S
1583 Rule Moncton 1940 only - May 19 1:00 1:00 D
1584 Rule Moncton 1941 only - May 4 1:00 1:00 D
1585 Rule Moncton 1946 1972 - Apr lastSun 2:00 1:00 D
1586 Rule Moncton 1946 1956 - Sep lastSun 2:00 0 S
1587 Rule Moncton 1957 1972 - Oct lastSun 2:00 0 S
1588 Rule Moncton 1993 2006 - Apr Sun>=1 0:01 1:00 D
1589 Rule Moncton 1993 2006 - Oct lastSun 0:01 0 S
1590 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1591 Zone America/Moncton -4:19:08 - LMT 1883 Dec 9
1592 -5:00 - EST 1902 Jun 15
1593 -4:00 Canada A%sT 1933
1594 -4:00 Moncton A%sT 1942
1595 -4:00 Canada A%sT 1946
1596 -4:00 Moncton A%sT 1973
1597 -4:00 Canada A%sT 1993
1598 -4:00 Moncton A%sT 2007
1603 # From Paul Eggert (2020-01-10):
1604 # See America/Toronto for most of Quebec, including Montreal.
1605 # See America/Halifax for the Îles de la Madeleine and the Listuguj reserve.
1606 # See America/Puerto_Rico for east of Natashquan.
1610 # From Mark Brader (2003-07-26):
1611 # [According to the Toronto Star] Orillia, Ontario, adopted DST
1612 # effective Saturday, 1912-06-22, 22:00; the article mentions that
1613 # Port Arthur (now part of Thunder Bay, Ontario) as well as Moose Jaw
1614 # have already done so. In Orillia DST was to run until Saturday,
1615 # 1912-08-31 (no time mentioned), but it was met with considerable
1616 # hostility from certain segments of the public, and was revoked after
1617 # only two weeks - I copied it as Saturday, 1912-07-07, 22:00, but
1618 # presumably that should be -07-06. (1912-06-19, -07-12; also letters
1621 # Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
1623 # From Paul Eggert (2017-07-08):
1624 # For more on Orillia, see: Daubs K. Bold attempt at daylight saving
1625 # time became a comic failure in Orillia. Toronto Star 2017-07-08.
1626 # https://www.thestar.com/news/insight/2017/07/08/bold-attempt-at-daylight-saving-time-became-a-comic-failure-in-orillia.html
1628 # From Mark Brader (2010-03-06):
1630 # In the (Toronto) Globe and Mail for Saturday, 1955-09-24, in the bottom
1631 # right corner of page 1, it says that Toronto will return to standard
1632 # time at 2 am Sunday morning (which agrees with the database), and that:
1634 # The one-hour setback will go into effect throughout most of Ontario,
1635 # except in areas like Windsor which remains on standard time all year.
1637 # ... I don't know if Windsor began observing DST when Detroit did,
1638 # or in 1974, or on some other date.
1640 # By the way, the article continues by noting that:
1642 # Some cities in the United States have pushed the deadline back
1643 # three weeks and will change over from daylight saving in October.
1645 # From Arthur David Olson (2010-07-17):
1647 # "Standard Time and Time Zones in Canada" appeared in
1648 # The Journal of The Royal Astronomical Society of Canada,
1649 # volume 26, number 2 (February 1932) and, as of 2010-07-17,
1651 # http://adsabs.harvard.edu/full/1932JRASC..26...49S
1653 # It includes the text below (starting on page 57):
1655 # A list of the places in Canada using daylight saving time would
1656 # require yearly revision. From information kindly furnished by
1657 # the provincial governments and by the postmasters in many cities
1658 # and towns, it is found that the following places used daylight sav-
1659 # ing in 1930. The information for the province of Quebec is definite,
1660 # for the other provinces only approximate:
1662 # Province Daylight saving time used
1663 # Prince Edward Island Not used.
1664 # Nova Scotia In Halifax only.
1665 # New Brunswick In St. John only.
1666 # Quebec In the following places:
1670 # St. Lambert Cap de la Madelèine
1671 # Verdun Loretteville
1672 # Westmount Richmond
1673 # Outremont St. Jérôme
1674 # Longueuil Greenfield Park
1676 # Chambly-Canton Beaulieu
1677 # Melbourne La Tuque
1678 # St. Théophile Buckingham
1679 # Ontario Used generally in the cities and towns along
1680 # the southerly part of the province. Not
1681 # used in the northwesterly part.
1682 # Manitoba Not used.
1683 # Saskatchewan In Regina only.
1685 # British Columbia Not used.
1687 # With some exceptions, the use of daylight saving may be said to be limited
1688 # to those cities and towns lying between Quebec city and Windsor, Ont.
1690 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1691 Rule Toronto 1919 only - Mar 30 23:30 1:00 D
1692 Rule Toronto 1919 only - Oct 26 0:00 0 S
1693 Rule Toronto 1920 only - May 2 2:00 1:00 D
1694 Rule Toronto 1920 only - Sep 26 0:00 0 S
1695 Rule Toronto 1921 only - May 15 2:00 1:00 D
1696 Rule Toronto 1921 only - Sep 15 2:00 0 S
1697 Rule Toronto 1922 1923 - May Sun>=8 2:00 1:00 D
1698 # Shanks & Pottenger say 1923-09-19; assume it's a typo and that "-16"
1700 Rule Toronto 1922 1926 - Sep Sun>=15 2:00 0 S
1701 Rule Toronto 1924 1927 - May Sun>=1 2:00 1:00 D
1702 Rule Toronto 1927 1937 - Sep Sun>=25 2:00 0 S
1703 Rule Toronto 1928 1937 - Apr Sun>=25 2:00 1:00 D
1704 Rule Toronto 1938 1940 - Apr lastSun 2:00 1:00 D
1705 Rule Toronto 1938 1939 - Sep lastSun 2:00 0 S
1706 Rule Toronto 1945 1946 - Sep lastSun 2:00 0 S
1707 Rule Toronto 1946 only - Apr lastSun 2:00 1:00 D
1708 Rule Toronto 1947 1949 - Apr lastSun 0:00 1:00 D
1709 Rule Toronto 1947 1948 - Sep lastSun 0:00 0 S
1710 Rule Toronto 1949 only - Nov lastSun 0:00 0 S
1711 Rule Toronto 1950 1973 - Apr lastSun 2:00 1:00 D
1712 Rule Toronto 1950 only - Nov lastSun 2:00 0 S
1713 Rule Toronto 1951 1956 - Sep lastSun 2:00 0 S
1714 # Shanks & Pottenger say Toronto ended DST a week early in 1971,
1715 # namely on 1971-10-24, but Mark Brader wrote (2003-05-31) that this
1716 # is wrong, and that he had confirmed it by checking the 1971-10-30
1717 # Toronto Star, which said that DST was ending 1971-10-31 as usual.
1718 Rule Toronto 1957 1973 - Oct lastSun 2:00 0 S
1720 # The Bahamas match Toronto since 1970.
1722 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1723 Zone America/Toronto -5:17:32 - LMT 1895
1724 -5:00 Canada E%sT 1919
1725 -5:00 Toronto E%sT 1942 Feb 9 2:00s
1726 -5:00 Canada E%sT 1946
1727 -5:00 Toronto E%sT 1974
1729 # For Atikokan see America/Panama.
1734 # From Rob Douglas (2006-04-06):
1735 # the old Manitoba Time Act - as amended by Bill 2, assented to
1736 # March 27, 1987 ... said ...
1737 # "between two o'clock Central Standard Time in the morning of
1738 # the first Sunday of April of each year and two o'clock Central
1739 # Standard Time in the morning of the last Sunday of October next
1740 # following, one hour in advance of Central Standard Time."...
1741 # I believe that the English legislation [of the old time act] had
1742 # been assented to (March 22, 1967)....
1743 # Also, as far as I can tell, there was no order-in-council varying
1744 # the time of Daylight Saving Time for 2005 and so the provisions of
1745 # the 1987 version would apply - the changeover was at 2:00 Central
1746 # Standard Time (i.e. not until 3:00 Central Daylight Time).
1748 # From Paul Eggert (2006-04-10):
1749 # Shanks & Pottenger say Manitoba switched at 02:00 (not 02:00s)
1750 # starting 1966. Since 02:00s is clearly correct for 1967 on, assume
1751 # it was also 02:00s in 1966.
1753 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1754 Rule Winn 1916 only - Apr 23 0:00 1:00 D
1755 Rule Winn 1916 only - Sep 17 0:00 0 S
1756 Rule Winn 1918 only - Apr 14 2:00 1:00 D
1757 Rule Winn 1918 only - Oct 27 2:00 0 S
1758 Rule Winn 1937 only - May 16 2:00 1:00 D
1759 Rule Winn 1937 only - Sep 26 2:00 0 S
1760 Rule Winn 1942 only - Feb 9 2:00 1:00 W # War
1761 Rule Winn 1945 only - Aug 14 23:00u 1:00 P # Peace
1762 Rule Winn 1945 only - Sep lastSun 2:00 0 S
1763 Rule Winn 1946 only - May 12 2:00 1:00 D
1764 Rule Winn 1946 only - Oct 13 2:00 0 S
1765 Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
1766 Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
1767 Rule Winn 1950 only - May 1 2:00 1:00 D
1768 Rule Winn 1950 only - Sep 30 2:00 0 S
1769 Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
1770 Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
1771 Rule Winn 1959 only - Oct lastSun 2:00 0 S
1772 Rule Winn 1960 only - Sep lastSun 2:00 0 S
1773 Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
1774 Rule Winn 1963 only - Sep 22 2:00 0 S
1775 Rule Winn 1966 1986 - Apr lastSun 2:00s 1:00 D
1776 Rule Winn 1966 2005 - Oct lastSun 2:00s 0 S
1777 Rule Winn 1987 2005 - Apr Sun>=1 2:00s 1:00 D
1778 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1779 Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
1780 -6:00 Winn C%sT 2006
1786 # From Mark Brader (2003-07-26):
1787 # The first actual adoption of DST in Canada was at the municipal
1788 # level. As the [Toronto] Star put it (1912-06-07), "While people
1789 # elsewhere have long been talking of legislation to save daylight,
1790 # the city of Moose Jaw [Saskatchewan] has acted on its own hook."
1791 # DST in Moose Jaw began on Saturday, 1912-06-01 (no time mentioned:
1792 # presumably late evening, as below), and would run until "the end of
1793 # the summer". The discrepancy between municipal time and railroad
1796 # From Paul Eggert (2003-07-27):
1797 # Willett (1914-03) notes that DST "has been in operation ... in the
1798 # City of Moose Jaw, Saskatchewan, for one year."
1800 # From Paul Eggert (2019-07-25):
1801 # Pearce's book says Regina observed DST in 1914-1917. No dates and times,
1802 # unfortunately. It also says that in 1914 Saskatoon observed DST
1803 # from 1 June to 6 July, and that DST was also tried out in Davidson,
1804 # Melfort, and Prince Albert.
1806 # From Paul Eggert (2006-03-22):
1807 # Shanks & Pottenger say that since 1970 this region has mostly been as Regina.
1808 # Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
1809 # Other western towns (e.g. Lloydminster) are like Edmonton.
1810 # Matthews and Vincent (1998) write that Denare Beach and Creighton
1811 # are like Winnipeg, in violation of Saskatchewan law.
1813 # From W. Jones (1992-11-06):
1814 # The. . .below is based on information I got from our law library, the
1815 # provincial archives, and the provincial Community Services department.
1816 # A precise history would require digging through newspaper archives, and
1817 # since you didn't say what you wanted, I didn't bother.
1819 # Saskatchewan is split by a time zone meridian (105W) and over the years
1820 # the boundary became pretty ragged as communities near it reevaluated
1821 # their affiliations in one direction or the other. In 1965 a provincial
1822 # referendum favoured legislating common time practices.
1824 # On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
1825 # Saskatchewan 1978) was proclaimed, and established that the eastern
1826 # part of Saskatchewan would use CST year round, that districts in
1827 # northwest Saskatchewan would by default follow CST but could opt to
1828 # follow Mountain Time rules (thus 1 hour difference in the winter and
1829 # zero in the summer), and that districts in southwest Saskatchewan would
1830 # by default follow MT but could opt to follow CST.
1832 # It took a few years for the dust to settle (I know one story of a town
1833 # on one time zone having its school in another, such that a mom had to
1834 # serve her family lunch in two shifts), but presently it seems that only
1835 # a few towns on the border with Alberta (e.g. Lloydminster) follow MT
1836 # rules any more; all other districts appear to have used CST year round
1837 # since sometime in the 1960s.
1839 # From Chris Walton (2006-06-26):
1840 # The Saskatchewan time act which was last updated in 1996 is about 30 pages
1841 # long and rather painful to read.
1842 # http://www.qp.gov.sk.ca/documents/English/Statutes/Statutes/T14.pdf
1844 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1845 Rule Regina 1918 only - Apr 14 2:00 1:00 D
1846 Rule Regina 1918 only - Oct 27 2:00 0 S
1847 Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
1848 Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
1849 Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
1850 Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
1851 Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
1852 Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
1853 Rule Regina 1942 only - Feb 9 2:00 1:00 W # War
1854 Rule Regina 1945 only - Aug 14 23:00u 1:00 P # Peace
1855 Rule Regina 1945 only - Sep lastSun 2:00 0 S
1856 Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
1857 Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
1858 Rule Regina 1947 1957 - Apr lastSun 2:00 1:00 D
1859 Rule Regina 1947 1957 - Sep lastSun 2:00 0 S
1860 Rule Regina 1959 only - Apr lastSun 2:00 1:00 D
1861 Rule Regina 1959 only - Oct lastSun 2:00 0 S
1863 Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
1864 Rule Swift 1957 only - Oct lastSun 2:00 0 S
1865 Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
1866 Rule Swift 1959 only - Oct lastSun 2:00 0 S
1867 Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
1868 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1869 Zone America/Regina -6:58:36 - LMT 1905 Sep
1870 -7:00 Regina M%sT 1960 Apr lastSun 2:00
1872 Zone America/Swift_Current -7:11:20 - LMT 1905 Sep
1873 -7:00 Canada M%sT 1946 Apr lastSun 2:00
1874 -7:00 Regina M%sT 1950
1875 -7:00 Swift M%sT 1972 Apr lastSun 2:00
1881 # From Alois Treindl (2019-07-19):
1882 # There was no DST in Alberta in 1967... Calgary Herald, 29 April 1967.
1883 # 1969, no DST, from Edmonton Journal 18 April 1969
1885 # From Paul Eggert (2019-07-25):
1886 # Pearce's book says that Alberta's 1948 Daylight Saving Act required
1887 # Mountain Standard Time without DST, and that "anyone who broke that law
1888 # could be fined up to $25 and costs". There seems to be no record of
1889 # anybody paying the fine. The law was not changed until an August 1971
1890 # plebiscite reinstituted DST in 1972. This story is also mentioned in:
1891 # Boyer JP. Forcing Choice: The Risky Reward of Referendums. Dundum. 2017.
1892 # ISBN 978-1459739123.
1894 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1895 Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
1896 Rule Edm 1918 only - Oct 27 2:00 0 S
1897 Rule Edm 1919 only - May 27 2:00 0 S
1898 Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
1899 Rule Edm 1920 only - Oct lastSun 2:00 0 S
1900 Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
1901 Rule Edm 1942 only - Feb 9 2:00 1:00 W # War
1902 Rule Edm 1945 only - Aug 14 23:00u 1:00 P # Peace
1903 Rule Edm 1945 only - Sep lastSun 2:00 0 S
1904 Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
1905 Rule Edm 1947 only - Sep lastSun 2:00 0 S
1906 Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
1907 Rule Edm 1972 2006 - Oct lastSun 2:00 0 S
1908 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1909 Zone America/Edmonton -7:33:52 - LMT 1906 Sep
1916 # From Paul Eggert (2006-03-22):
1917 # Shanks & Pottenger write that since 1970 most of this region has
1918 # been like Vancouver.
1919 # Dawson Creek uses MST. Much of east BC is like Edmonton.
1921 # From Matt Johnson (2015-09-21):
1922 # Fort Nelson, BC, Canada will cancel DST this year. So while previously they
1923 # were aligned with America/Vancouver, they're now aligned with
1924 # America/Dawson_Creek.
1925 # http://www.northernrockies.ca/EN/meta/news/archives/2015/northern-rockies-time-change.html
1927 # From Tim Parenti (2015-09-23):
1928 # This requires a new zone for the Northern Rockies Regional Municipality,
1929 # America/Fort_Nelson. The resolution of 2014-12-08 was reached following a
1930 # 2014-11-15 poll with nearly 75% support. Effectively, the municipality has
1931 # been on MST (-0700) like Dawson Creek since it advanced its clocks on
1934 # From Paul Eggert (2019-07-25):
1935 # Shanks says Fort Nelson did not observe DST in 1946, unlike Vancouver.
1936 # Alois Treindl confirmed this on 07-22, citing the 1946-04-27 Vancouver Daily
1937 # Province. He also cited the 1946-09-28 Victoria Daily Times, which said
1938 # that Vancouver, Victoria, etc. "change at midnight Saturday"; for now,
1939 # guess they meant 02:00 Sunday since 02:00 was common practice in Vancouver.
1941 # Early Vancouver, Volume Four, by Major J.S. Matthews, V.D., 2011 edition
1942 # says that a 1922 plebiscite adopted DST, but a 1923 plebiscite rejected it.
1943 # http://former.vancouver.ca/ctyclerk/archives/digitized/EarlyVan/SearchEarlyVan/Vol4pdf/MatthewsEarlyVancouverVol4_DaylightSavings.pdf
1944 # A catalog entry for a newspaper clipping seems to indicate that Vancouver
1945 # observed DST in 1941 from 07-07 through 09-27; see
1946 # https://searcharchives.vancouver.ca/daylight-saving-1918-starts-again-july-7-1941-start-d-s-sept-27-end-of-d-s-1941
1947 # We have no further details, so omit them for now.
1949 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
1950 Rule Vanc 1918 only - Apr 14 2:00 1:00 D
1951 Rule Vanc 1918 only - Oct 27 2:00 0 S
1952 Rule Vanc 1942 only - Feb 9 2:00 1:00 W # War
1953 Rule Vanc 1945 only - Aug 14 23:00u 1:00 P # Peace
1954 Rule Vanc 1945 only - Sep 30 2:00 0 S
1955 Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
1956 Rule Vanc 1946 only - Sep 29 2:00 0 S
1957 Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
1958 Rule Vanc 1962 2006 - Oct lastSun 2:00 0 S
1959 # Zone NAME STDOFF RULES FORMAT [UNTIL]
1960 Zone America/Vancouver -8:12:28 - LMT 1884
1961 -8:00 Vanc P%sT 1987
1963 Zone America/Dawson_Creek -8:00:56 - LMT 1884
1964 -8:00 Canada P%sT 1947
1965 -8:00 Vanc P%sT 1972 Aug 30 2:00
1967 Zone America/Fort_Nelson -8:10:47 - LMT 1884
1968 -8:00 Vanc P%sT 1946
1970 -8:00 Vanc P%sT 1987
1971 -8:00 Canada P%sT 2015 Mar 8 2:00
1973 # For Creston see America/Phoenix.
1975 # Northwest Territories, Nunavut, Yukon
1977 # From Chris Walton (2022-11-06):
1978 # Whitehorse Star - Thursday April 22, 1965 - page 1
1979 # title: DST Starts Monday ...
1980 # https://www.newspapers.com/image/578587481/
1981 # The title of this first article is wrong and/or misleading.
1982 # Also, the start time shown in the article is vague; it simply says "after
1983 # midnight" when it probably should have stated 2:00a.m....
1985 # Whitehorse Star - Monday October 25, 1965 - page 15 ...
1986 # https://www.newspapers.com/image/578589147/
1987 # The 1965 Yukon Council minutes can be found here:
1988 # http://assets.yukonarchives.ca/PER_YG_06_1965_C20_S02_v1.pdf
1989 # ... I do not currently believe that NWT touched any of its clocks in 1965....
1991 # Whitehorse Star - Thursday Feb 24,1966 - page 2
1992 # title: It's Time for YDT ...
1993 # https://www.newspapers.com/image/578575979/ ...
1994 # America/Whitehorse as a permanent change from UTC-9(YST) to
1995 # UTC-8(PST) at 00:00 on Sunday February 27, 1966....
1997 # Whitehorse Star - Friday April 28,1972 - page 6
1998 # title: Daylight Saving Time for N.W.T....
1999 # https://www.newspapers.com/image/578701610/ ...
2000 # Nunavut and NWT zones ... DST starting in 1972.... Start and End ...
2001 # should be the same as the rest of Canada
2004 # From Paul Eggert (2022-11-06):
2005 # For now, assume Yukon's 1965-04-22 spring forward was 00:00 -> 02:00, as this
2006 # seems likely than 02:00 -> 04:00 and matches "after midnight".
2008 # From Paul Eggert (2006-03-22):
2009 # Dawson switched to PST in 1973. Inuvik switched to MST in 1979.
2010 # Mathew Englander (1996-10-07) gives the following refs:
2011 # * 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
2012 # c. 7 defines Yukon standard time as UTC-9....
2013 # see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
2014 # [https://www.canlii.org/en/ca/laws/stat/rsc-1985-c-i-21/latest/rsc-1985-c-i-21.html]
2015 # * C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
2016 # * O.I.C. 1980/02 established DST.
2017 # * O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
2019 # From Brian Inglis (2015-04-14):
2021 # I tried to trace the history of Yukon time and found the following
2022 # regulations, giving the reference title and URL if found, regulation name,
2023 # and relevant quote if available. Each regulation specifically revokes its
2024 # predecessor. The final reference is to the current Interpretation Act
2025 # authorizing and resulting from these regulatory changes.
2027 # Only recent regulations were retrievable via Yukon government site search or
2028 # index, and only some via Canadian legal sources. Other sources used include
2029 # articles titled "Standard Time and Time Zones in Canada" from JRASC via ADS
2030 # Abstracts, cited by ADO for 1932 ..., and updated versions from 1958 and
2031 # 1970 quoted below; each article includes current extracts from provincial
2032 # and territorial ST and DST regulations at the end, summaries and details of
2033 # standard times and daylight saving time at many locations across Canada,
2034 # with time zone maps, tables and calculations for Canadian Sunrise, Sunset,
2035 # and LMST; they also cover many countries and global locations, with a chart
2036 # and table showing current Universal Time offsets, and may be useful as
2037 # another source of information for 1970 and earlier.
2039 # * Standard Time and Time Zones in Canada; Smith, C.C.; JRASC, Vol. 26,
2040 # pp.49-77; February 1932; SAO/NASA Astrophysics Data System (ADS)
2041 # http://adsabs.harvard.edu/abs/1932JRASC..26...49S from p.75:
2042 # Yukon Interpretation Ordinance
2043 # Yukon standard time is the local mean time at the one hundred and
2044 # thirty-fifth meridian.
2046 # * Standard Time and Time Zones in Canada; Smith, C.C.; Thomson, Malcolm M.;
2047 # JRASC, Vol. 52, pp.193-223; October 1958; SAO/NASA Astrophysics Data System
2048 # (ADS) http://adsabs.harvard.edu/abs/1958JRASC..52..193S from pp.220-1:
2049 # Yukon Interpretation Ordinance, 1955, Chap. 16.
2051 # (1) Subject to this section, standard time shall be reckoned as nine
2052 # hours behind Greenwich Time and called Yukon Standard Time.
2054 # (2) Notwithstanding subsection (1), the Commissioner may make regulations
2055 # varying the manner of reckoning standard time.
2057 # * Yukon Territory Commissioner's Order 1966-20 Interpretation Ordinance
2058 # [no online source found]
2060 # * Standard Time and Time Zones in Canada; Thomson, Malcolm M.; JRASC,
2061 # Vol. 64, pp.129-162; June 1970; SAO/NASA Astrophysics Data System (ADS)
2062 # http://adsabs.harvard.edu/abs/1970JRASC..64..129T from p.156: Yukon
2063 # Territory Commissioner's Order 1967-59 Interpretation Ordinance ...
2065 # 1. Commissioner's Order 1966-20 dated at Whitehorse in the Yukon
2066 # Territory on 27th January, 1966, is hereby revoked.
2068 # 2. Yukon (East) Standard Time as defined by section 36 of the
2069 # Interpretation Ordinance from and after mid-night on the 28th day of May,
2070 # 1967 shall be reckoned in the same manner as Pacific Standard Time, that
2071 # is to say, eight hours behind Greenwich Time in the area of the Yukon
2072 # Territory lying east of the 138th degree longitude west.
2074 # 3. In the remainder of the Territory, lying west of the 138th degree
2075 # longitude west, Yukon (West) Standard Time shall be reckoned as nine
2076 # hours behind Greenwich Time.
2078 # * Yukon Standard Time defined as Pacific Standard Time, YCO 1973/214
2079 # https://www.canlii.org/en/yk/laws/regu/yco-1973-214/latest/yco-1973-214.html
2080 # C.O. 1973/214 INTERPRETATION ACT ...
2082 # 1. Effective October 28, 1973 Commissioner's Order 1967/59 is hereby
2085 # 2. Yukon Standard Time as defined by section 36 of the Interpretation
2086 # Act from and after midnight on the twenty-eighth day of October, 1973
2087 # shall be reckoned in the same manner as Pacific Standard Time, that is
2088 # to say eight hours behind Greenwich Time.
2090 # * O.I.C. 1980/02 INTERPRETATION ACT
2091 # https://mm.icann.org/pipermail/tz/attachments/20201125/d5adc93b/CAYTOIC1980-02DST1980-01-04-0001.pdf
2093 # * Yukon Daylight Saving Time, YOIC 1987/56
2094 # https://www.canlii.org/en/yk/laws/regu/yoic-1987-56/latest/yoic-1987-56.html
2095 # O.I.C. 1987/056 INTERPRETATION ACT ...
2097 # In every year between
2098 # (a) two o'clock in the morning in the first Sunday in April, and
2099 # (b) two o'clock in the morning in the last Sunday in October,
2100 # Standard Time shall be reckoned as seven hours behind Greenwich Time and
2101 # called Yukon Daylight Saving Time.
2103 # Dated ... 9th day of March, A.D., 1987.
2105 # * Yukon Daylight Saving Time 2006, YOIC 2006/127
2106 # https://www.canlii.org/en/yk/laws/regu/yoic-2006-127/latest/yoic-2006-127.html
2107 # O.I.C. 2006/127 INTERPRETATION ACT ...
2109 # 1. In Yukon each year the time for general purposes shall be 7 hours
2110 # behind Greenwich mean time during the period commencing at two o'clock
2111 # in the forenoon on the second Sunday of March and ending at two o'clock
2112 # in the forenoon on the first Sunday of November and shall be called
2113 # Yukon Daylight Saving Time.
2115 # 2. Order-in-Council 1987/56 is revoked.
2117 # 3. This order comes into force January 1, 2007.
2119 # * Interpretation Act, RSY 2002, c 125
2120 # https://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html
2122 # From Chris Walton (2022-11-06):
2123 # The 5th edition of the Atlas of Canada contains a time zone map that
2124 # shows both legislated and observed time zone boundaries.
2125 # All communities on Baffin Island are shown to be observing Eastern time.
2126 # The date on the map is 1984.
2127 # https://ftp.maps.canada.ca/pub/nrcan_rncan/raster/atlas_5_ed/eng/other/referencemaps/mcr4056.pdf
2129 # From Rives McDow (1999-09-04):
2130 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
2131 # Nunavut moves to single time zone Oct. 31
2132 # http://www.nunatsiaq.com/nunavut/nvt90903_13.html
2134 # From Paul Eggert (1999-09-20):
2135 # Basic Facts: The New Territory
2136 # http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html
2137 # (1999) reports that ... Coral Harbour does not observe DST.
2139 # From Paul Eggert (2000-10-02):
2140 # Matthews and Vincent (1998) say the following, but we lack histories
2141 # for these potential new Zones.
2143 # The Canadian Forces station at Alert uses Eastern Time while the
2144 # handful of residents at the Eureka weather station [in the Central
2145 # zone] skip daylight savings. Baffin Island, which is crossed by the
2146 # Central, Eastern and Atlantic Time zones only uses Eastern Time.
2147 # Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
2148 # Central Time and Southampton Island [in the Central zone] is not
2149 # required to use daylight savings.
2151 # From <http://www.nunatsiaqonline.ca/archives/nunavut001130/nvt21110_02.html>
2152 # Nunavut now has two time zones (2000-11-10):
2153 # The Nunavut government would allow its employees in Kugluktuk and
2154 # Cambridge Bay to operate on central time year-round, putting them
2155 # one hour behind the rest of Nunavut for six months during the winter.
2156 # At the end of October the two communities had rebelled against
2157 # Nunavut's unified time zone, refusing to shift to eastern time with
2158 # the rest of the territory for the winter. Cambridge Bay remained on
2159 # central time, while Kugluktuk, even farther west, reverted to
2160 # mountain time, which they had used before the advent of Nunavut's
2161 # unified time zone in 1999.
2163 # From Rives McDow (2001-01-20), quoting the Nunavut government:
2164 # The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
2166 # From Paul Eggert (2000-12-04):
2167 # Let's just keep track of the official times for now.
2169 # From Rives McDow (2001-03-07):
2170 # The premier of Nunavut has issued a ministerial statement advising
2171 # that effective 2001-04-01, the territory of Nunavut will revert
2172 # back to three time zones (mountain, central, and eastern). Of the
2173 # cities in Nunavut, Coral Harbor is the only one that I know of that
2174 # has said it will not observe dst, staying on EST year round. I'm
2175 # checking for more info, and will get back to you if I come up with
2177 # [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]
2179 # From Gwillim Law (2005-05-21):
2181 # http://www.canadiangeographic.ca/Magazine/SO98/geomap.asp
2182 # (from a 1998 Canadian Geographic article), the de facto and de jure time
2183 # for Southampton Island (at the north end of Hudson Bay) is UTC-5 all year
2184 # round. Using Google, it's easy to find other websites that confirm this.
2185 # I wasn't able to find how far back this time regimen goes, but since it
2186 # predates the creation of Nunavut, it probably goes back many years....
2187 # The Inuktitut name of Coral Harbour is Sallit, but it's rarely used.
2189 # From Paul Eggert (2014-10-17):
2190 # For lack of better information, assume that Southampton Island observed
2191 # daylight saving only during wartime. Gwillim Law's email also
2192 # mentioned maps now maintained by National Research Council Canada;
2193 # see above for an up-to-date link.
2195 # From Chris Walton (2007-03-01):
2196 # ... the community of Resolute (located on Cornwallis Island in
2197 # Nunavut) moved from Central Time to Eastern Time last November.
2198 # Basically the community did not change its clocks at the end of
2199 # daylight saving....
2200 # http://www.nnsl.com/frames/newspapers/2006-11/nov13_06none.html
2202 # From Chris Walton (2011-03-21):
2203 # Back in 2007 I initiated the creation of a new "zone file" for Resolute
2204 # Bay. Resolute Bay is a small community located about 900km north of
2205 # the Arctic Circle. The zone file was required because Resolute Bay had
2206 # decided to use UTC-5 instead of UTC-6 for the winter of 2006-2007.
2208 # According to new information which I received last week, Resolute Bay
2209 # went back to using UTC-6 in the winter of 2007-2008...
2211 # On March 11/2007 most of Canada went onto daylight saving. On March
2212 # 14/2007 I phoned the Resolute Bay hamlet office to do a "time check." I
2213 # talked to somebody that was both knowledgeable and helpful. I was able
2214 # to confirm that Resolute Bay was still operating on UTC-5. It was
2215 # explained to me that Resolute Bay had been on the Eastern Time zone
2216 # (EST) in the winter, and was now back on the Central Time zone (CDT).
2217 # i.e. the time zone had changed twice in the last year but the clocks
2218 # had not moved. The residents had to know which time zone they were in
2219 # so they could follow the correct TV schedule...
2221 # On Nov 02/2008 most of Canada went onto standard time. On Nov 03/2008 I
2222 # phoned the Resolute Bay hamlet office...[D]ue to the challenging nature
2223 # of the phone call, I decided to seek out an alternate source of
2224 # information. I found an e-mail address for somebody by the name of
2225 # Stephanie Adams whose job was listed as "Inns North Support Officer for
2226 # Arctic Co-operatives." I was under the impression that Stephanie lived
2227 # and worked in Resolute Bay...
2229 # On March 14/2011 I phoned the hamlet office again. I was told that
2230 # Resolute Bay had been using Central Standard Time over the winter of
2231 # 2010-2011 and that the clocks had therefore been moved one hour ahead
2232 # on March 13/2011. The person I talked to was aware that Resolute Bay
2233 # had previously experimented with Eastern Standard Time but he could not
2234 # tell me when the practice had stopped.
2236 # On March 17/2011 I searched the Web to find an e-mail address of
2237 # somebody that might be able to tell me exactly when Resolute Bay went
2238 # off Eastern Standard Time. I stumbled on the name "Aziz Kheraj." Aziz
2239 # used to be the mayor of Resolute Bay and he apparently owns half the
2240 # businesses including "South Camp Inn." This website has some info on
2242 # http://www.uphere.ca/node/493
2244 # I sent Aziz an e-mail asking when Resolute Bay had stopped using
2245 # Eastern Standard Time.
2247 # Aziz responded quickly with this: "hi, The time was not changed for the
2248 # 1 year only, the following year, the community went back to the old way
2249 # of "spring ahead-fall behind" currently we are zulu plus 5 hrs and in
2250 # the winter Zulu plus 6 hrs"
2252 # This of course conflicted with everything I had ascertained in November 2008.
2254 # I sent Aziz a copy of my 2008 e-mail exchange with Stephanie. Aziz
2255 # responded with this: "Hi, Stephanie lives in Winnipeg. I live here, You
2256 # may want to check with the weather office in Resolute Bay or do a
2257 # search on the weather through Env. Canada. web site"
2259 # If I had realized the Stephanie did not live in Resolute Bay I would
2260 # never have contacted her. I now believe that all the information I
2261 # obtained in November 2008 should be ignored...
2262 # I apologize for reporting incorrect information in 2008.
2264 # From Tim Parenti (2020-03-05):
2265 # The government of Yukon announced [yesterday] the cessation of seasonal time
2266 # changes. "After clocks are pushed ahead one hour on March 8, the territory
2267 # will remain on [UTC-07]. ... [The government] found 93 per cent of
2268 # respondents wanted to end seasonal time changes and, of that group, 70 per
2269 # cent wanted 'permanent Pacific Daylight Saving Time.'"
2270 # https://www.cbc.ca/news/canada/north/yukon-end-daylight-saving-time-1.5486358
2272 # Although the government press release prefers PDT, we prefer MST for
2273 # consistency with nearby Dawson Creek, Creston, and Fort Nelson.
2274 # https://yukon.ca/en/news/yukon-end-seasonal-time-change
2276 # From Andrew G. Smith (2020-09-24):
2277 # Yukon has completed its regulatory change to be on UTC -7 year-round....
2278 # http://www.gov.yk.ca/legislation/regs/oic2020_125.pdf
2279 # What we have done is re-defined Yukon Standard Time, as we are
2280 # authorized to do under section 33 of our Interpretation Act:
2281 # http://www.gov.yk.ca/legislation/acts/interpretation_c.pdf
2283 # From Paul Eggert (2020-09-24):
2284 # tzdb uses the obsolete YST abbreviation for standard time in Yukon through
2285 # about 1970, and uses PST for standard time in Yukon since then. Consistent
2286 # with that, use MST for -07, the new standard time in Yukon effective Nov. 1.
2288 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2289 Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
2290 Rule NT_YK 1918 only - Oct 27 2:00 0 S
2291 Rule NT_YK 1919 only - May 25 2:00 1:00 D
2292 Rule NT_YK 1919 only - Nov 1 0:00 0 S
2293 Rule NT_YK 1942 only - Feb 9 2:00 1:00 W # War
2294 Rule NT_YK 1945 only - Aug 14 23:00u 1:00 P # Peace
2295 Rule NT_YK 1945 only - Sep 30 2:00 0 S
2296 Rule NT_YK 1972 1986 - Apr lastSun 2:00 1:00 D
2297 Rule NT_YK 1972 2006 - Oct lastSun 2:00 0 S
2298 Rule NT_YK 1987 2006 - Apr Sun>=1 2:00 1:00 D
2299 Rule Yukon 1965 only - Apr lastSun 0:00 2:00 DD
2300 Rule Yukon 1965 only - Oct lastSun 2:00 0 S
2301 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2302 # formerly Frobisher Bay
2303 Zone America/Iqaluit 0 - -00 1942 Aug # Frobisher Bay est.
2304 -5:00 NT_YK E%sT 1999 Oct 31 2:00
2305 -6:00 Canada C%sT 2000 Oct 29 2:00
2308 Zone America/Resolute 0 - -00 1947 Aug 31 # Resolute founded
2309 -6:00 NT_YK C%sT 2000 Oct 29 2:00
2310 -5:00 - EST 2001 Apr 1 3:00
2311 -6:00 Canada C%sT 2006 Oct 29 2:00
2312 -5:00 - EST 2007 Mar 11 3:00
2315 Zone America/Rankin_Inlet 0 - -00 1957 # Rankin Inlet founded
2316 -6:00 NT_YK C%sT 2000 Oct 29 2:00
2317 -5:00 - EST 2001 Apr 1 3:00
2319 # aka Iqaluktuuttiaq
2320 Zone America/Cambridge_Bay 0 - -00 1920 # trading post est.?
2321 -7:00 NT_YK M%sT 1999 Oct 31 2:00
2322 -6:00 Canada C%sT 2000 Oct 29 2:00
2323 -5:00 - EST 2000 Nov 5 0:00
2324 -6:00 - CST 2001 Apr 1 3:00
2326 Zone America/Inuvik 0 - -00 1953 # Inuvik founded
2327 -8:00 NT_YK P%sT 1979 Apr lastSun 2:00
2328 -7:00 NT_YK M%sT 1980
2330 Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20
2331 -9:00 NT_YK Y%sT 1965
2332 -9:00 Yukon Y%sT 1966 Feb 27 0:00
2334 -8:00 Canada P%sT 2020 Nov 1
2336 Zone America/Dawson -9:17:40 - LMT 1900 Aug 20
2337 -9:00 NT_YK Y%sT 1965
2338 -9:00 Yukon Y%sT 1973 Oct 28 0:00
2340 -8:00 Canada P%sT 2020 Nov 1
2344 ###############################################################################
2348 # From Paul Eggert (2014-12-07):
2349 # The Investigation and Analysis Service of the
2350 # Mexican Library of Congress (MLoC) has published a
2351 # history of Mexican local time (in Spanish)
2352 # http://www.diputados.gob.mx/bibliot/publica/inveyana/polisoc/horver/index.htm
2354 # Here are the discrepancies between Shanks & Pottenger (S&P) and the MLoC.
2355 # (In all cases we go with the MLoC.)
2356 # S&P report that Baja was at -8:00 in 1922/1923.
2357 # S&P say the 1930 transition in Baja was 1930-11-16.
2358 # S&P report no DST during summer 1931.
2359 # S&P report a transition at 1932-03-30 23:00, not 1932-04-01.
2361 # From Gwillim Law (2001-02-20):
2362 # There are some other discrepancies between the Decrees page and the
2363 # tz database. I think they can best be explained by supposing that
2364 # the researchers who prepared the Decrees page failed to find some of
2365 # the relevant documents.
2367 # From Alan Perry (1996-02-15):
2368 # A guy from our Mexico subsidiary finally found the Presidential Decree
2369 # outlining the timezone changes in Mexico.
2371 # ------------- Begin Forwarded Message -------------
2373 # I finally got my hands on the Official Presidential Decree that sets up the
2374 # rules for the DST changes. The rules are:
2376 # 1. The country is divided in 3 timezones:
2377 # - Baja California Norte (the Mexico/BajaNorte TZ)
2378 # - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
2379 # - The rest of the country (the Mexico/General TZ)
2381 # 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
2382 # at 2:00 AM, the times in each zone are as follows:
2387 # 3. The rest of the year, the times are as follows:
2392 # The Decree was published in Mexico's Official Newspaper on January 4th.
2394 # -------------- End Forwarded Message --------------
2395 # From Paul Eggert (1996-06-12):
2396 # For an English translation of the decree, see
2397 # "Diario Oficial: Time Zone Changeover" (1996-01-04).
2398 # http://mexico-travel.com/extra/timezone_eng.html
2400 # From Rives McDow (1998-10-08):
2401 # The State of Quintana Roo has reverted back to central STD and DST times
2402 # (i.e. UTC -0600 and -0500 as of 1998-08-02).
2404 # From Rives McDow (2000-01-10):
2405 # Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
2406 # zone 5 hours from the International Date Line, and will not observe daylight
2407 # savings time so as to stay on the same time zone as the southern part of
2408 # Arizona year round.
2410 # From Jesper Nørgaard, translating
2411 # <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
2412 # In Oaxaca, the 55.000 teachers from the Section 22 of the National
2413 # Syndicate of Education Workers, refuse to apply daylight saving each
2414 # year, so that the more than 10,000 schools work at normal hour the
2417 # From Gwillim Law (2001-01-19):
2418 # <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
2420 # January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
2421 # that Summer Time will be reduced from seven to five months, starting
2423 # http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001
2424 # [translated], says "summer time will ... take effect on the first Sunday
2425 # in May, and end on the last Sunday of September.
2427 # From Arthur David Olson (2001-01-25):
2428 # The 2001-01-24 traditional Washington Post contained the page one
2429 # story "Timely Issue Divides Mexicans."...
2430 # http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
2431 # ... Mexico City Mayor López Obrador "...is threatening to keep
2432 # Mexico City and its 20 million residents on a different time than
2433 # the rest of the country..." In particular, López Obrador would abolish
2434 # observation of Daylight Saving Time.
2436 # Official statute published by the Energy Department
2437 # http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre
2438 # (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
2439 # and Sonora with no DST. This was reported by Jesper Nørgaard (2001-02-03).
2441 # From Paul Eggert (2001-03-03):
2443 # https://www.latimes.com/archives/la-xpm-2001-mar-03-mn-32561-story.html
2444 # James F. Smith writes in today's LA Times
2445 # * Sonora will continue to observe standard time.
2446 # * Last week Mexico City's mayor Andrés Manuel López Obrador decreed that
2447 # the Federal District will not adopt DST.
2448 # * 4 of 16 district leaders announced they'll ignore the decree.
2449 # * The decree does not affect federal-controlled facilities including
2450 # the airport, banks, hospitals, and schools.
2452 # For now we'll assume that the Federal District will bow to federal rules.
2454 # From Jesper Nørgaard (2001-04-01):
2455 # I found some references to the Mexican application of daylight
2456 # saving, which modifies what I had already sent you, stating earlier
2457 # that a number of northern Mexican states would go on daylight
2458 # saving. The modification reverts this to only cover Baja California
2459 # (Norte), while all other states (except Sonora, who has no daylight
2460 # saving all year) will follow the original decree of president
2461 # Vicente Fox, starting daylight saving May 6, 2001 and ending
2462 # September 30, 2001.
2463 # References: "Diario de Monterrey" <http://www.diariodemonterrey.com/index.asp>
2464 # Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2001-03-31)
2466 # From Reuters (2001-09-04):
2467 # Mexico's Supreme Court on Tuesday declared that daylight savings was
2468 # unconstitutional in Mexico City, creating the possibility the
2469 # capital will be in a different time zone from the rest of the nation
2470 # next year.... The Supreme Court's ruling takes effect at 2:00
2471 # a.m. (0800 GMT) on Sept. 30, when Mexico is scheduled to revert to
2472 # standard time. "This is so residents of the Federal District are not
2473 # subject to unexpected time changes," a statement from the court said.
2475 # From Jesper Nørgaard Welen (2002-03-12):
2476 # ... consulting my local grocery store(!) and my coworkers, they all insisted
2477 # that a new decision had been made to reinstate US style DST in Mexico....
2478 # http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html (2002-02-20)
2479 # confirms this. Sonora as usual is the only state where DST is not applied.
2481 # From Steffen Thorsen (2009-12-28):
2483 # Steffen Thorsen wrote:
2484 # > Mexico's House of Representatives has approved a proposal for northern
2485 # > Mexico's border cities to share the same daylight saving schedule as
2486 # > the United States.
2487 # Now this has passed both the Congress and the Senate, so starting from
2488 # 2010, some border regions will be the same:
2489 # http://www.signonsandiego.com/news/2009/dec/28/clocks-will-match-both-sides-border/
2490 # http://www.elmananarey.com/diario/noticia/nacional/noticias/empatan_horario_de_frontera_con_eu/621939
2493 # Could not find the new law text, but the proposed law text changes are here:
2494 # http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/20091210-V.pdf
2495 # (Gaceta Parlamentaria)
2497 # There is also a list of the votes here:
2498 # http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/V2-101209.html
2501 # https://www.timeanddate.com/news/time/north-mexico-dst-change.html
2503 # From Arthur David Olson (2010-01-20):
2505 # http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
2506 # includes this text:
2507 # En los municipios fronterizos de Tijuana y Mexicali en Baja California;
2508 # Juárez y Ojinaga en Chihuahua; Acuña y Piedras Negras en Coahuila;
2509 # Anáhuac en Nuevo León; y Nuevo Laredo, Reynosa y Matamoros en
2510 # Tamaulipas, la aplicación de este horario estacional surtirá efecto
2511 # desde las dos horas del segundo domingo de marzo y concluirá a las dos
2512 # horas del primer domingo de noviembre.
2513 # En los municipios fronterizos que se encuentren ubicados en la franja
2514 # fronteriza norte en el territorio comprendido entre la línea
2515 # internacional y la línea paralela ubicada a una distancia de veinte
2516 # kilómetros, así como la Ciudad de Ensenada, Baja California, hacia el
2517 # interior del país, la aplicación de este horario estacional surtirá
2518 # efecto desde las dos horas del segundo domingo de marzo y concluirá a
2519 # las dos horas del primer domingo de noviembre.
2521 # From Steffen Thorsen (2014-12-08), translated by Gwillim Law:
2522 # The Mexican state of Quintana Roo will likely change to EST in 2015.
2524 # http://www.unioncancun.mx/articulo/2014/12/04/medio-ambiente/congreso-aprueba-una-hora-mas-de-sol-en-qroo
2525 # "With this change, the time conflict that has existed between the municipios
2526 # of Quintana Roo and the municipio of Felipe Carrillo Puerto may come to an
2527 # end. The latter declared itself in rebellion 15 years ago when a time change
2528 # was initiated in Mexico, and since then it has refused to change its time
2529 # zone along with the rest of the country."
2531 # From Steffen Thorsen (2015-01-14), translated by Gwillim Law:
2532 # http://sipse.com/novedades/confirman-aplicacion-de-nueva-zona-horaria-para-quintana-roo-132331.html
2533 # "...the new time zone will come into effect at two o'clock on the first Sunday
2534 # of February, when we will have to advance the clock one hour from its current
2536 # Also, the new zone will not use DST.
2538 # From Carlos Raúl Perasso (2015-02-02):
2539 # The decree that modifies the Mexican Hour System Law has finally
2540 # been published at the Diario Oficial de la Federación
2541 # http://www.dof.gob.mx/nota_detalle.php?codigo=5380123&fecha=31/01/2015
2542 # It establishes 5 zones for Mexico:
2543 # 1- Zona Centro (Central Zone): Corresponds to longitude 90 W,
2544 # includes most of Mexico, excluding what's mentioned below.
2545 # 2- Zona Pacífico (Pacific Zone): Longitude 105 W, includes the
2546 # states of Baja California Sur; Chihuahua; Nayarit (excluding Bahía
2547 # de Banderas which lies in Central Zone); Sinaloa and Sonora.
2548 # 3- Zona Noroeste (Northwest Zone): Longitude 120 W, includes the
2549 # state of Baja California.
2550 # 4- Zona Sureste (Southeast Zone): Longitude 75 W, includes the state
2552 # 5- The islands, reefs and keys shall take their timezone from the
2553 # longitude they are located at.
2555 # From Paul Eggert (2022-10-28):
2556 # The new Mexican law was published today:
2557 # https://www.dof.gob.mx/nota_detalle.php?codigo=5670045&fecha=28/10/2022
2558 # This abolishes DST except where US DST rules are observed,
2559 # and in addition changes all of Chihuahua to -06 with no DST.
2561 # From Heitor David Pinto (2022-11-28):
2562 # Now the northern [municipios] want to have the same time zone as the
2563 # respective neighboring cities in the US, for example Juárez in UTC-7 with
2564 # DST, matching El Paso, and Ojinaga in UTC-6 with DST, matching Presidio....
2565 # the president authorized the publication of the decree for November 29,
2566 # so the time change would occur on November 30 at 0:00.
2567 # http://puentelibre.mx/noticia/ciudad_juarez_cambio_horario_noviembre_2022/
2569 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2570 Rule Mexico 1931 only - May 1 23:00 1:00 D
2571 Rule Mexico 1931 only - Oct 1 0:00 0 S
2572 Rule Mexico 1939 only - Feb 5 0:00 1:00 D
2573 Rule Mexico 1939 only - Jun 25 0:00 0 S
2574 Rule Mexico 1940 only - Dec 9 0:00 1:00 D
2575 Rule Mexico 1941 only - Apr 1 0:00 0 S
2576 Rule Mexico 1943 only - Dec 16 0:00 1:00 W # War
2577 Rule Mexico 1944 only - May 1 0:00 0 S
2578 Rule Mexico 1950 only - Feb 12 0:00 1:00 D
2579 Rule Mexico 1950 only - Jul 30 0:00 0 S
2580 Rule Mexico 1996 2000 - Apr Sun>=1 2:00 1:00 D
2581 Rule Mexico 1996 2000 - Oct lastSun 2:00 0 S
2582 Rule Mexico 2001 only - May Sun>=1 2:00 1:00 D
2583 Rule Mexico 2001 only - Sep lastSun 2:00 0 S
2584 Rule Mexico 2002 2022 - Apr Sun>=1 2:00 1:00 D
2585 Rule Mexico 2002 2022 - Oct lastSun 2:00 0 S
2586 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2587 # Quintana Roo; represented by Cancún
2588 Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 6:00u
2589 -6:00 - CST 1981 Dec 23
2590 -5:00 Mexico E%sT 1998 Aug 2 2:00
2591 -6:00 Mexico C%sT 2015 Feb 1 2:00
2593 # Campeche, Yucatán; represented by Mérida
2594 Zone America/Merida -5:58:28 - LMT 1922 Jan 1 6:00u
2595 -6:00 - CST 1981 Dec 23
2596 -5:00 - EST 1982 Dec 2
2598 # Coahuila, Nuevo León, Tamaulipas (near US border)
2599 # This includes the following municipios:
2600 # in Coahuila: Acuña, Allende, Guerrero, Hidalgo, Jiménez, Morelos, Nava,
2601 # Ocampo, Piedras Negras, Villa Unión, Zaragoza
2602 # in Nuevo León: Anáhuac
2603 # in Tamaulipas: Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo,
2604 # Gustavo Díaz Ordaz, Reynosa, Río Bravo, Valle Hermoso, Matamoros.
2605 # https://www.dof.gob.mx/nota_detalle.php?codigo=5670045&fecha=28/10/2022
2606 Zone America/Matamoros -6:30:00 - LMT 1922 Jan 1 6:00u
2609 -6:00 Mexico C%sT 2010
2611 # Durango; Coahuila, Nuevo León, Tamaulipas (away from US border)
2612 Zone America/Monterrey -6:41:16 - LMT 1922 Jan 1 6:00u
2617 Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 7:00u
2618 -7:00 - MST 1927 Jun 10 23:00
2619 -6:00 - CST 1930 Nov 15
2620 -7:00 Mexico M%sT 1932 Apr 1
2621 -6:00 Mexico C%sT 2001 Sep 30 2:00
2622 -6:00 - CST 2002 Feb 20
2624 # Chihuahua (near US border - western side)
2625 # This includes the municipios of Janos, Ascensión, Juárez, Guadalupe, and
2626 # Práxedis G Guerrero.
2627 # http://gaceta.diputados.gob.mx/PDF/65/2a022/nov/20221124-VII.pdf
2628 Zone America/Ciudad_Juarez -7:05:56 - LMT 1922 Jan 1 7:00u
2629 -7:00 - MST 1927 Jun 10 23:00
2630 -6:00 - CST 1930 Nov 15
2631 -7:00 Mexico M%sT 1932 Apr 1
2633 -6:00 Mexico C%sT 1998
2634 -6:00 - CST 1998 Apr Sun>=1 3:00
2635 -7:00 Mexico M%sT 2010
2636 -7:00 US M%sT 2022 Oct 30 2:00
2637 -6:00 - CST 2022 Nov 30 0:00
2639 # Chihuahua (near US border - eastern side)
2640 # This includes the municipios of Coyame del Sotol, Ojinaga, and Manuel
2642 # http://gaceta.diputados.gob.mx/PDF/65/2a022/nov/20221124-VII.pdf
2643 Zone America/Ojinaga -6:57:40 - LMT 1922 Jan 1 7:00u
2644 -7:00 - MST 1927 Jun 10 23:00
2645 -6:00 - CST 1930 Nov 15
2646 -7:00 Mexico M%sT 1932 Apr 1
2648 -6:00 Mexico C%sT 1998
2649 -6:00 - CST 1998 Apr Sun>=1 3:00
2650 -7:00 Mexico M%sT 2010
2651 -7:00 US M%sT 2022 Oct 30 2:00
2652 -6:00 - CST 2022 Nov 30 0:00
2654 # Chihuahua (away from US border)
2655 Zone America/Chihuahua -7:04:20 - LMT 1922 Jan 1 7:00u
2656 -7:00 - MST 1927 Jun 10 23:00
2657 -6:00 - CST 1930 Nov 15
2658 -7:00 Mexico M%sT 1932 Apr 1
2660 -6:00 Mexico C%sT 1998
2661 -6:00 - CST 1998 Apr Sun>=1 3:00
2662 -7:00 Mexico M%sT 2022 Oct 30 2:00
2665 Zone America/Hermosillo -7:23:52 - LMT 1922 Jan 1 7:00u
2666 -7:00 - MST 1927 Jun 10 23:00
2667 -6:00 - CST 1930 Nov 15
2668 -7:00 Mexico M%sT 1932 Apr 1
2669 -6:00 - CST 1942 Apr 24
2670 -7:00 - MST 1949 Jan 14
2672 -7:00 Mexico M%sT 1999
2675 # Baja California Sur, Nayarit (except Bahía de Banderas), Sinaloa
2676 Zone America/Mazatlan -7:05:40 - LMT 1922 Jan 1 7:00u
2677 -7:00 - MST 1927 Jun 10 23:00
2678 -6:00 - CST 1930 Nov 15
2679 -7:00 Mexico M%sT 1932 Apr 1
2680 -6:00 - CST 1942 Apr 24
2681 -7:00 - MST 1949 Jan 14
2687 # From Alexander Krivenyshev (2010-04-21):
2688 # According to news, Bahía de Banderas (Mexican state of Nayarit)
2689 # changed time zone UTC-7 to new time zone UTC-6 on April 4, 2010 (to
2690 # share the same time zone as nearby city Puerto Vallarta, Jalisco).
2693 # Bahía de Banderas homologa su horario al del centro del
2694 # país, a partir de este domingo
2695 # http://www.nayarit.gob.mx/notes.asp?id=20748
2697 # Bahía de Banderas homologa su horario con el del Centro del
2699 # http://www.bahiadebanderas.gob.mx/principal/index.php?option=com_content&view=article&id=261:bahia-de-banderas-homologa-su-horario-con-el-del-centro-del-pais&catid=42:comunicacion-social&Itemid=50
2702 # Puerto Vallarta and Bahía de Banderas: One Time Zone
2703 # http://virtualvallarta.com/puertovallarta/puertovallarta/localnews/2009-12-03-Puerto-Vallarta-and-Bahia-de-Banderas-One-Time-Zone.shtml
2704 # http://www.worldtimezone.com/dst_news/dst_news_mexico08.html
2706 # "Mexico's Senate approved the amendments to the Mexican Schedule System that
2707 # will allow Bahía de Banderas and Puerto Vallarta to share the same time
2709 # Baja California Sur, Nayarit, Sinaloa
2711 # From Arthur David Olson (2010-05-01):
2712 # Use "Bahia_Banderas" to keep the name to fourteen characters.
2714 Zone America/Bahia_Banderas -7:01:00 - LMT 1922 Jan 1 7:00u
2715 -7:00 - MST 1927 Jun 10 23:00
2716 -6:00 - CST 1930 Nov 15
2717 -7:00 Mexico M%sT 1932 Apr 1
2718 -6:00 - CST 1942 Apr 24
2719 -7:00 - MST 1949 Jan 14
2721 -7:00 Mexico M%sT 2010 Apr 4 2:00
2725 Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 7:00u
2727 -8:00 - PST 1927 Jun 10 23:00
2728 -7:00 - MST 1930 Nov 15
2729 -8:00 - PST 1931 Apr 1
2730 -8:00 1:00 PDT 1931 Sep 30
2731 -8:00 - PST 1942 Apr 24
2732 -8:00 1:00 PWT 1945 Aug 14 23:00u
2733 -8:00 1:00 PPT 1945 Nov 12 # Peace
2734 -8:00 - PST 1948 Apr 5
2735 -8:00 1:00 PDT 1949 Jan 14
2740 -8:00 Mexico P%sT 2001
2741 -8:00 US P%sT 2002 Feb 20
2742 -8:00 Mexico P%sT 2010
2744 # From Paul Eggert (2006-03-22):
2745 # Formerly there was an America/Ensenada zone, which differed from
2746 # America/Tijuana only in that it did not observe DST from 1976
2747 # through 1995. This was as per Shanks (1999). But Shanks & Pottenger say
2748 # Ensenada did not observe DST from 1948 through 1975. Guy Harris reports
2749 # that the 1987 OAG says "Only Ensenada, Mexicali, San Felipe and
2750 # Tijuana observe DST," which agrees with Shanks & Pottenger but implies that
2751 # DST-observance was a town-by-town matter back then. This concerns
2752 # data after 1970 so most likely there should be at least one Zone
2753 # other than America/Tijuana for Baja, but it's not clear yet what its
2754 # name or contents should be.
2756 # From Paul Eggert (2015-10-08):
2757 # Formerly there was an America/Santa_Isabel zone, but this appears to
2758 # have come from a misreading of
2759 # http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
2760 # It has been moved to the 'backward' file.
2762 # From Paul Eggert (2022-10-28):
2763 # Today's new law states that the entire state of Baja California
2764 # follows US DST rules, which agrees with simplifications noted above.
2770 ###############################################################################
2774 # For 1899 Milne gives -3:58:29.2.
2776 # From P Chan (2020-12-09 and 2020-12-11):
2777 # Standard time of GMT-4 was adopted in 1911.
2778 # Definition of Time Act, 1911 (1911-7) [1911-08-28]
2779 # 1912, Laws of Barbados (5 v.), OCLC Number: 919801291, Vol. 4, Image No. 522
2780 # 1944, Laws of Barbados (5 v.), OCLC Number: 84548697, Vol. 4, Image No. 122
2781 # http://llmc.com/browse.aspx?type=2&coll=85&div=297
2783 # DST was observed in 1942-44.
2784 # Defence (Daylight Saving) Regulations, 1942, 1942-04-13
2785 # Defence (Daylight Saving) (Repeal) Regulations, 1942, 1942-08-22
2786 # Defence (Daylight Saving) Regulations, 1943, 1943-04-16
2787 # Defence (Daylight Saving) (Repeal) Regulations, 1943, 1943-09-01
2788 # Defence (Daylight Saving) Regulations, 1944, 1944-03-21
2789 # [Defence (Daylight Saving) (Amendment) Regulations 1944, 1944-03-28]
2790 # Defence (Daylight Saving) (Repeal) Regulations, 1944, 1944-08-30
2792 # 1914-, Subsidiary Legis., Annual Vols. OCLC Number: 226290591
2793 # 1942: Image Nos. 527-528, 555-556
2794 # 1943: Image Nos. 178-179, 198
2795 # 1944: Image Nos. 113-115, 129
2796 # http://llmc.com/titledescfull.aspx?type=2&coll=85&div=297&set=98437
2798 # From Tim Parenti (2021-02-20):
2799 # The transitions below are derived from P Chan's sources, except that the 1977
2800 # through 1980 transitions are from Shanks & Pottenger since we have no better
2801 # data there. Of particular note, the 1944 DST regulation only advanced the
2802 # time to "exactly three and a half hours later than Greenwich mean time", as
2803 # opposed to "three hours" in the 1942 and 1943 regulations.
2805 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2806 Rule Barb 1942 only - Apr 19 5:00u 1:00 D
2807 Rule Barb 1942 only - Aug 31 6:00u 0 S
2808 Rule Barb 1943 only - May 2 5:00u 1:00 D
2809 Rule Barb 1943 only - Sep 5 6:00u 0 S
2810 Rule Barb 1944 only - Apr 10 5:00u 0:30 -
2811 Rule Barb 1944 only - Sep 10 6:00u 0 S
2812 Rule Barb 1977 only - Jun 12 2:00 1:00 D
2813 Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
2814 Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
2815 Rule Barb 1979 only - Sep 30 2:00 0 S
2816 Rule Barb 1980 only - Sep 25 2:00 0 S
2817 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2819 Zone America/Barbados -3:58:29 - LMT 1911 Aug 28 # Bridgetown
2820 -4:00 Barb A%sT 1944
2821 -4:00 Barb AST/-0330 1945
2826 # From P Chan (2020-11-03):
2827 # Below are some laws related to the time in British Honduras/Belize:
2829 # Definition of Time Ordinance, 1927 (No.4 of 1927) [1927-04-01]
2830 # Ordinances of British Honduras Passed in the Year 1927, p 19-20
2831 # https://books.google.com/books?id=LqEpAQAAMAAJ&pg=RA3-PA19
2833 # Definition of Time (Amendment) Ordinance, 1942 (No. 5 of 1942) [1942-06-27]
2834 # Ordinances of British Honduras Passed in the Year 1942, p 31-32
2835 # https://books.google.com/books?id=h6MpAQAAMAAJ&pg=RA6-PA95-IA44
2837 # Definition of Time Ordinance, 1945 (No. 19 of 1945) [1945-12-15]
2838 # Ordinances of British Honduras Passed in the Year 1945, p 49-50
2839 # https://books.google.com/books?id=xaMpAQAAMAAJ&pg=RA2-PP1
2841 # Definition of Time Ordinance, 1947 (No. 1 of 1947) [1947-03-11]
2842 # Ordinances of British Honduras Passed in the Year 1947, p 1-2
2843 # https://books.google.com/books?id=xaMpAQAAMAAJ&pg=RA3-PA1
2845 # Time (Definition of) Ordinance (Chapter 180)
2846 # The Laws of British Honduras in Force on the 15th Day of September, 1958 , Volume IV, p 2580
2847 # https://books.google.com/books?id=v5QpAQAAMAAJ&pg=PA2580
2849 # Time (Definition of) (Amendment) Ordinance, 1968 (No. 13 of 1968) [1968-08-03]
2850 # https://books.google.com/books?id=xij7KEB_58wC&pg=RA1-PA428-IA9
2852 # Definition of Time Act (Chapter 339)
2853 # Law of Belize, Revised Edition 2000
2854 # http://www.belizelaw.org/web/lawadmin/PDF%20files/cap339.pdf
2856 # From Paul Eggert (2020-11-03):
2857 # The transitions below are derived from P Chan's sources, except that the
2858 # 1973 through 1983 transitions are from Shanks & Pottenger since we have
2859 # no better data there.
2861 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2862 Rule Belize 1918 1941 - Oct Sat>=1 24:00 0:30 -0530
2863 Rule Belize 1919 1942 - Feb Sat>=8 24:00 0 CST
2864 Rule Belize 1942 only - Jun 27 24:00 1:00 CWT
2865 Rule Belize 1945 only - Aug 14 23:00u 1:00 CPT
2866 Rule Belize 1945 only - Dec 15 24:00 0 CST
2867 Rule Belize 1947 1967 - Oct Sat>=1 24:00 0:30 -0530
2868 Rule Belize 1948 1968 - Feb Sat>=8 24:00 0 CST
2869 Rule Belize 1973 only - Dec 5 0:00 1:00 CDT
2870 Rule Belize 1974 only - Feb 9 0:00 0 CST
2871 Rule Belize 1982 only - Dec 18 0:00 1:00 CDT
2872 Rule Belize 1983 only - Feb 12 0:00 0 CST
2873 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2874 Zone America/Belize -5:52:48 - LMT 1912 Apr 1
2879 # From Paul Eggert (2022-07-27):
2880 # For 1899 Milne gives -4:19:18.3 as the meridian of the clock tower,
2881 # Bermuda dockyard, Ireland I. This agrees with standard offset given in the
2882 # Daylight Saving Act, 1917 cited below.
2883 # It is not known when this time became standard for Bermuda; guess 1890.
2884 # The transition to -04 was specified by:
2885 # 1930: The Time Zone Act, 1929 (1929: No. 39) [1929-11-08]
2886 # https://books.google.com/books?id=7tdMAQAAIAAJ&pg=RA54-PP1
2888 # From P Chan (2020-11-20):
2889 # Most of the information can be found online from the Bermuda National
2890 # Library - Digital Collection which includes The Royal Gazette (RG) until 1957
2891 # https://bnl.contentdm.oclc.org/digital/
2892 # I will cite the ID. For example, [10000] means
2893 # https://bnl.contentdm.oclc.org/digital/collection/BermudaNP02/id/10000
2895 # 1917: Apr 5 midnight to Sep 30 midnight
2896 # Daylight Saving Act, 1917 (1917 No. 13) [1917-04-02]
2897 # Bermuda Acts and Resolves 1917, p 37-38
2898 # https://books.google.com/books?id=M-lCAQAAMAAJ&pg=PA36-IA2
2899 # RG, 1917-04-04, p 6 [42340] gives the spring forward date.
2901 # 1918: Apr 13 midnight to Sep 15 midnight
2902 # Daylight Saving Act, 1918 (1918 No. 9) [1918-04-06]
2903 # Bermuda Acts and Resolves 1917, p 13
2904 # https://books.google.com/books?id=K-lCAQAAMAAJ&pg=RA1-PA7
2906 # Note that local mean time was still used before 1930.
2908 # During WWII, DST was introduced by Defence Regulations
2909 # 1942: Jan 11 02:00 to Oct 18 02:00 [113646], [115726]
2910 # 1943: Mar 21 02:00 to Oct 31 02:00 [116704], [118193]
2911 # 1944: Mar 12 02:00 to Nov 5 02:00 [119225], [121593]
2912 # 1945: Mar 11 02:00 to Nov 4 02:00 [122369], [124461]
2913 # RG, 1942-01-08, p 2, 1942-10-12, p 2 , 1943-03-06, p 2, 1943-09-03, p 1,
2914 # 1944-02-29, p 6, 1944-09-20, p 2, 1945-02-13, p 2, 1945-11-03, p 1
2916 # In 1946, the House of Assembly rejected DST twice. [128686], [128076]
2917 # RG, 1946-03-16 p 1,1946-04-13 p 1
2919 # 1947: third Sunday in May 02:00 to second Sunday in September 02:00
2920 # DST in 1947 was defined in the Daylight Saving Act, 1947 (1947: No. 12)
2921 # which expired at the end of the year. [125784] ,[132405], [144454], [138226]
2922 # RG, 1947-02-27, p 1, 1947-05-15, p 1, 1947-09-13, p 1, 1947-12-30, p 1
2924 # 1948-1952: fourth Sunday in May 02:00 to first Sunday in September 02:00
2925 # DST in 1948 was defined in the Daylight Saving Act, 1948 (1948 : No. 12)
2926 # which was set to expired at the end of the year but it was extended until
2927 # the end of 1952 and was not further extended.
2928 # [129802], [139403], [146008], [135240], [144330], [139049], [143309],
2929 # [148271], [149773], [153589], [153802], [155924]
2930 # RG, 1948-04-13, p 1, 1948-05-22, p 1, 1948-09-04, p 1, 1949-05-21, p1,
2931 # 1949-09-03, p 1, 1950-05-27 p 1, 1950-09-02, p 1, 1951-05-27, p 1,
2932 # 1951-09-01, p 1, 1952-05-23, p 1, 1952-09-26, p 1, 1952-12-21, p 8
2934 # In 1953-1955, the House of Assembly rejected DST each year. [158996],
2935 # [162620], [166720] RG, 1953-05-02, p 1, 1954-04-01 p 1, 1955-03-12, p 1
2937 # 1956: fourth Sunday in May 02:00 to last Sunday in October 02:00
2938 # Time Zone (Seasonal Variation) Act, 1956 (1956: No.44) [1956-05-25]
2939 # Bermuda Public Acts 1956, p 331-332
2940 # https://books.google.com/books?id=Xs1AlmD_cEwC&pg=PA63
2942 # The extension of the Act was rejected by the House of Assembly. [176218]
2943 # RG, 1956-12-13, p 1
2945 # From the Chronological Table of Public and Private Acts up to 1985, it seems
2946 # that there does not exist other Acts related to DST before 1973.
2947 # https://books.google.com/books?id=r9hMAQAAIAAJ&pg=RA23-PA1
2948 # Public Acts of the Legislature of the Islands of Bermuda, Together with
2949 # Statutory Instruments in Force Thereunder, Vol VII
2951 # From Dan Jones, reporting in The Royal Gazette (2006-06-26):
2952 # Next year, however, clocks in the US will go forward on the second Sunday
2953 # in March, until the first Sunday in November. And, after the Time Zone
2954 # (Seasonal Variation) Bill 2006 was passed in the House of Assembly on
2955 # Friday, the same thing will happen in Bermuda.
2956 # http://www.theroyalgazette.com/apps/pbcs.dll/article?AID=/20060529/NEWS/105290135
2958 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2959 Rule Bermuda 1917 only - Apr 5 24:00 1:00 -
2960 Rule Bermuda 1917 only - Sep 30 24:00 0 -
2961 Rule Bermuda 1918 only - Apr 13 24:00 1:00 -
2962 Rule Bermuda 1918 only - Sep 15 24:00 0 S
2963 Rule Bermuda 1942 only - Jan 11 2:00 1:00 D
2964 Rule Bermuda 1942 only - Oct 18 2:00 0 S
2965 Rule Bermuda 1943 only - Mar 21 2:00 1:00 D
2966 Rule Bermuda 1943 only - Oct 31 2:00 0 S
2967 Rule Bermuda 1944 1945 - Mar Sun>=8 2:00 1:00 D
2968 Rule Bermuda 1944 1945 - Nov Sun>=1 2:00 0 S
2969 Rule Bermuda 1947 only - May Sun>=15 2:00 1:00 D
2970 Rule Bermuda 1947 only - Sep Sun>=8 2:00 0 S
2971 Rule Bermuda 1948 1952 - May Sun>=22 2:00 1:00 D
2972 Rule Bermuda 1948 1952 - Sep Sun>=1 2:00 0 S
2973 Rule Bermuda 1956 only - May Sun>=22 2:00 1:00 D
2974 Rule Bermuda 1956 only - Oct lastSun 2:00 0 S
2976 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2978 Zone Atlantic/Bermuda -4:19:18 - LMT 1890 # Hamilton
2979 -4:19:18 Bermuda BMT/BST 1930 Jan 1 2:00
2980 -4:00 Bermuda A%sT 1974 Apr 28 2:00
2981 -4:00 Canada A%sT 1976
2986 # Milne gives -5:36:13.3 as San José mean time.
2988 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
2989 Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
2990 Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
2991 Rule CR 1991 1992 - Jan Sat>=15 0:00 1:00 D
2992 # IATA SSIM (1991-09) says the following was at 1:00;
2993 # go with Shanks & Pottenger.
2994 Rule CR 1991 only - Jul 1 0:00 0 S
2995 Rule CR 1992 only - Mar 15 0:00 0 S
2996 # There are too many San Josés elsewhere, so we'll use 'Costa Rica'.
2997 # Zone NAME STDOFF RULES FORMAT [UNTIL]
2999 Zone America/Costa_Rica -5:36:13 - LMT 1890 # San José
3000 -5:36:13 - SJMT 1921 Jan 15 # San José Mean Time
3003 # no information; probably like America/Costa_Rica
3007 # From Paul Eggert (2013-02-21):
3008 # Milne gives -5:28:50.45 for the observatory at Havana, -5:29:23.57
3009 # for the port, and -5:30 for meteorological observations.
3010 # For now, stick with Shanks & Pottenger.
3012 # From Arthur David Olson (1999-03-29):
3013 # The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
3014 # the Cuban National Team and the Baltimore Orioles was carried live on
3015 # the Orioles Radio Network, including affiliate WTOP in Washington, DC.
3016 # During the game, play-by-play announcer Jim Hunter noted that
3017 # "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
3018 # Time today." (The "two hour" remark referred to losing one hour of
3019 # sleep on 1999-03-28 - when the announcers were in Cuba as it switched
3020 # to DST - and one more hour on 1999-04-04 - when the announcers will have
3021 # returned to Baltimore, which switches on that date.)
3023 # From Steffen Thorsen (2013-11-11):
3024 # DST start in Cuba in 2004 ... does not follow the same rules as the
3025 # years before. The correct date should be Sunday 2004-03-28 00:00 ...
3026 # https://web.archive.org/web/20040402060750/http://www.granma.cu/espanol/2004/marzo/sab27/reloj.html
3028 # From Evert van der Veer via Steffen Thorsen (2004-10-28):
3029 # Cuba is not going back to standard time this year.
3030 # From Paul Eggert (2006-03-22):
3031 # http://www.granma.cu/ingles/2004/septiembre/juev30/41medid-i.html
3032 # says that it's due to a problem at the Antonio Guiteras
3033 # thermoelectric plant, and says "This October there will be no return
3034 # to normal hours (after daylight saving time)".
3035 # For now, let's assume that it's a temporary measure.
3037 # From Carlos A. Carnero Delgado (2005-11-12):
3038 # This year (just like in 2004-2005) there's no change in time zone
3039 # adjustment in Cuba. We will stay in daylight saving time:
3040 # http://www.granma.cu/espanol/2005/noviembre/mier9/horario.html
3042 # From Jesper Nørgaard Welen (2006-10-21):
3043 # An article in GRANMA INTERNACIONAL claims that Cuba will end
3044 # the 3 years of permanent DST next weekend, see
3045 # http://www.granma.cu/ingles/2006/octubre/lun16/43horario.html
3046 # "On Saturday night, October 28 going into Sunday, October 29, at 01:00,
3047 # watches should be set back one hour - going back to 00:00 hours - returning
3048 # to the normal schedule....
3050 # From Paul Eggert (2007-03-02):
3051 # <http://www.granma.cubaweb.cu/english/news/art89.html>, dated yesterday,
3052 # says Cuban clocks will advance at midnight on March 10.
3053 # For lack of better information, assume Cuba will use US rules,
3054 # except that it switches at midnight standard time as usual.
3056 # From Steffen Thorsen (2007-10-25):
3057 # Carlos Alberto Fonseca Arauz informed me that Cuba will end DST one week
3058 # earlier - on the last Sunday of October, just like in 2006.
3060 # He supplied these references:
3062 # http://www.prensalatina.com.mx/article.asp?ID={4CC32C1B-A9F7-42FB-8A07-8631AFC923AF}&language=ES
3063 # http://actualidad.terra.es/sociedad/articulo/cuba_llama_ahorrar_energia_cambio_1957044.htm
3065 # From Alex Krivenyshev (2007-10-25):
3066 # Here is also article from Granma (Cuba):
3068 # Regirá el Horario Normal desde el próximo domingo 28 de octubre
3069 # http://www.granma.cubaweb.cu/2007/10/24/nacional/artic07.html
3071 # http://www.worldtimezone.com/dst_news/dst_news_cuba03.html
3073 # From Arthur David Olson (2008-03-09):
3074 # I'm in Maryland which is now observing United States Eastern Daylight
3075 # Time. At 9:44 local time I used RealPlayer to listen to
3076 # http://media.enet.cu/radioreloj
3077 # a Cuban information station, and heard
3078 # the time announced as "ocho cuarenta y cuatro" ("eight forty-four"),
3079 # indicating that Cuba is still on standard time.
3081 # From Steffen Thorsen (2008-03-12):
3082 # It seems that Cuba will start DST on Sunday, 2007-03-16...
3083 # It was announced yesterday, according to this source (in Spanish):
3084 # http://www.nnc.cubaweb.cu/marzo-2008/cien-1-11-3-08.htm
3086 # Some more background information is posted here:
3087 # https://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
3089 # The article also says that Cuba has been observing DST since 1963,
3090 # while Shanks (and tzdata) has 1965 as the first date (except in the
3091 # 1940's). Many other web pages in Cuba also claim that it has been
3092 # observed since 1963, but with the exception of 1970 - an exception
3093 # which is not present in tzdata/Shanks. So there is a chance we need to
3094 # change some historic records as well.
3097 # http://www.radiohc.cu/espanol/noticias/mar07/11mar/hor.htm
3099 # From Jesper Nørgaard Welen (2008-03-13):
3100 # The Cuban time change has just been confirmed on the most authoritative
3101 # web site, the Granma. Please check out
3102 # http://www.granma.cubaweb.cu/2008/03/13/nacional/artic10.html
3104 # Basically as expected after Steffen Thorsen's information, the change
3105 # will take place midnight between Saturday and Sunday.
3107 # From Arthur David Olson (2008-03-12):
3108 # Assume Sun>=15 (third Sunday) going forward.
3110 # From Alexander Krivenyshev (2009-03-04)
3111 # According to the Radio Reloj - Cuba will start Daylight Saving Time on
3112 # midnight between Saturday, March 07, 2009 and Sunday, March 08, 2009-
3113 # not on midnight March 14 / March 15 as previously thought.
3115 # http://www.worldtimezone.com/dst_news/dst_news_cuba05.html
3118 # From Arthur David Olson (2009-03-09)
3119 # I listened over the Internet to
3120 # http://media.enet.cu/readioreloj
3121 # this morning; when it was 10:05 a. m. here in Bethesda, Maryland the
3122 # the time was announced as "diez cinco" - the same time as here, indicating
3123 # that has indeed switched to DST. Assume second Sunday from 2009 forward.
3125 # From Steffen Thorsen (2011-03-08):
3126 # Granma announced that Cuba is going to start DST on 2011-03-20 00:00:00
3127 # this year. Nothing about the end date known so far (if that has
3131 # http://granma.co.cu/2011/03/08/nacional/artic01.html
3134 # https://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
3136 # From Steffen Thorsen (2011-10-30)
3137 # Cuba will end DST two weeks later this year. Instead of going back
3138 # tonight, it has been delayed to 2011-11-13 at 01:00.
3140 # One source (Spanish)
3141 # http://www.radioangulo.cu/noticias/cuba/17105-cuba-restablecera-el-horario-del-meridiano-de-greenwich.html
3144 # https://www.timeanddate.com/news/time/cuba-time-changes-2011.html
3146 # From Steffen Thorsen (2012-03-01)
3147 # According to Radio Reloj, Cuba will start DST on Midnight between March
3150 # Radio Reloj has the following info (Spanish):
3151 # http://www.radioreloj.cu/index.php/noticias-radio-reloj/71-miscelaneas/7529-cuba-aplicara-el-horario-de-verano-desde-el-1-de-abril
3154 # https://www.timeanddate.com/news/time/cuba-starts-dst-2012.html
3156 # From Steffen Thorsen (2012-11-03):
3157 # Radio Reloj and many other sources report that Cuba is changing back
3158 # to standard time on 2012-11-04:
3159 # http://www.radioreloj.cu/index.php/noticias-radio-reloj/36-nacionales/9961-regira-horario-normal-en-cuba-desde-el-domingo-cuatro-de-noviembre
3160 # From Paul Eggert (2012-11-03):
3161 # For now, assume the future rule is first Sunday in November.
3163 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3164 Rule Cuba 1928 only - Jun 10 0:00 1:00 D
3165 Rule Cuba 1928 only - Oct 10 0:00 0 S
3166 Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
3167 Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
3168 Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
3169 Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
3170 Rule Cuba 1965 only - Jun 1 0:00 1:00 D
3171 Rule Cuba 1965 only - Sep 30 0:00 0 S
3172 Rule Cuba 1966 only - May 29 0:00 1:00 D
3173 Rule Cuba 1966 only - Oct 2 0:00 0 S
3174 Rule Cuba 1967 only - Apr 8 0:00 1:00 D
3175 Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
3176 Rule Cuba 1968 only - Apr 14 0:00 1:00 D
3177 Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
3178 Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
3179 Rule Cuba 1972 1974 - Oct 8 0:00 0 S
3180 Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
3181 Rule Cuba 1978 only - May 7 0:00 1:00 D
3182 Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
3183 Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
3184 Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
3185 Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
3186 Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
3187 Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
3188 Rule Cuba 1996 only - Oct 6 0:00s 0 S
3189 Rule Cuba 1997 only - Oct 12 0:00s 0 S
3190 Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D
3191 Rule Cuba 1998 2003 - Oct lastSun 0:00s 0 S
3192 Rule Cuba 2000 2003 - Apr Sun>=1 0:00s 1:00 D
3193 Rule Cuba 2004 only - Mar lastSun 0:00s 1:00 D
3194 Rule Cuba 2006 2010 - Oct lastSun 0:00s 0 S
3195 Rule Cuba 2007 only - Mar Sun>=8 0:00s 1:00 D
3196 Rule Cuba 2008 only - Mar Sun>=15 0:00s 1:00 D
3197 Rule Cuba 2009 2010 - Mar Sun>=8 0:00s 1:00 D
3198 Rule Cuba 2011 only - Mar Sun>=15 0:00s 1:00 D
3199 Rule Cuba 2011 only - Nov 13 0:00s 0 S
3200 Rule Cuba 2012 only - Apr 1 0:00s 1:00 D
3201 Rule Cuba 2012 max - Nov Sun>=1 0:00s 0 S
3202 Rule Cuba 2013 max - Mar Sun>=8 0:00s 1:00 D
3204 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3205 Zone America/Havana -5:29:28 - LMT 1890
3206 -5:29:36 - HMT 1925 Jul 19 12:00 # Havana MT
3209 # Dominican Republic
3211 # From Steffen Thorsen (2000-10-30):
3212 # Enrique Morales reported to me that the Dominican Republic has changed the
3213 # time zone to Eastern Standard Time as of Sunday 29 at 2 am....
3214 # http://www.listin.com.do/antes/261000/republica/princi.html
3216 # From Paul Eggert (2000-12-04):
3217 # That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
3219 # From Rives McDow (2000-12-01):
3220 # Dominican Republic changed its mind and presidential decree on Tuesday,
3221 # November 28, 2000, with a new decree. On Sunday, December 3 at 1:00 AM the
3222 # Dominican Republic will be reverting to 8 hours from the International Date
3223 # Line, and will not be using DST in the foreseeable future. The reason they
3224 # decided to use DST was to be in synch with Puerto Rico, who was also going
3225 # to implement DST. When Puerto Rico didn't implement DST, the president
3226 # decided to revert.
3229 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3230 Rule DR 1966 only - Oct 30 0:00 1:00 EDT
3231 Rule DR 1967 only - Feb 28 0:00 0 EST
3232 Rule DR 1969 1973 - Oct lastSun 0:00 0:30 -0430
3233 Rule DR 1970 only - Feb 21 0:00 0 EST
3234 Rule DR 1971 only - Jan 20 0:00 0 EST
3235 Rule DR 1972 1974 - Jan 21 0:00 0 EST
3236 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3237 Zone America/Santo_Domingo -4:39:36 - LMT 1890
3238 -4:40 - SDMT 1933 Apr 1 12:00 # S. Dom. MT
3239 -5:00 DR %s 1974 Oct 27
3240 -4:00 - AST 2000 Oct 29 2:00
3241 -5:00 US E%sT 2000 Dec 3 1:00
3246 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3247 Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
3248 Rule Salv 1987 1988 - Sep lastSun 0:00 0 S
3249 # There are too many San Salvadors elsewhere, so use America/El_Salvador
3250 # instead of America/San_Salvador.
3251 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3252 Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
3257 # From Gwillim Law (2006-04-22), after a heads-up from Oscar van Vlijmen:
3258 # Diario Co Latino, at
3259 # <http://www.diariocolatino.com/internacionales/detalles.asp?NewsID=8079>,
3260 # says in an article dated 2006-04-19 that the Guatemalan government had
3261 # decided on that date to advance official time by 60 minutes, to lessen the
3262 # impact of the elevated cost of oil.... Daylight saving time will last from
3263 # 2006-04-29 24:00 (Guatemalan standard time) to 2006-09-30 (time unspecified).
3264 # From Paul Eggert (2006-06-22):
3265 # The Ministry of Energy and Mines, press release CP-15/2006
3266 # (2006-04-19), says DST ends at 24:00. See
3267 # http://www.sieca.org.gt/Sitio_publico/Energeticos/Doc/Medidas/Cambio_Horario_Nac_190406.pdf
3269 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3270 Rule Guat 1973 only - Nov 25 0:00 1:00 D
3271 Rule Guat 1974 only - Feb 24 0:00 0 S
3272 Rule Guat 1983 only - May 21 0:00 1:00 D
3273 Rule Guat 1983 only - Sep 22 0:00 0 S
3274 Rule Guat 1991 only - Mar 23 0:00 1:00 D
3275 Rule Guat 1991 only - Sep 7 0:00 0 S
3276 Rule Guat 2006 only - Apr 30 0:00 1:00 D
3277 Rule Guat 2006 only - Oct 1 0:00 0 S
3278 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3279 Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
3283 # From Gwillim Law (2005-04-15):
3284 # Risto O. Nykänen wrote me that Haiti is now on DST.
3285 # I searched for confirmation, and I found a press release
3286 # on the Web page of the Haitian Consulate in Chicago (2005-03-31),
3287 # <http://www.haitianconsulate.org/time.doc>. Translated from French, it says:
3289 # "The Prime Minister's Communication Office notifies the public in general
3290 # and the press in particular that, following a decision of the Interior
3291 # Ministry and the Territorial Collectivities [I suppose that means the
3292 # provinces], Haiti will move to Eastern Daylight Time in the night from next
3293 # Saturday the 2nd to Sunday the 3rd.
3295 # "Consequently, the Prime Minister's Communication Office wishes to inform
3296 # the population that the country's clocks will be set forward one hour
3297 # starting at midnight. This provision will hold until the last Saturday in
3300 # "Port-au-Prince, March 31, 2005"
3302 # From Steffen Thorsen (2006-04-04):
3303 # I have been informed by users that Haiti observes DST this year like
3304 # last year, so the current "only" rule for 2005 might be changed to a
3305 # "max" rule or to last until 2006. (Who knows if they will observe DST
3306 # next year or if they will extend their DST like US/Canada next year).
3308 # I have found this article about it (in French):
3309 # http://www.haitipressnetwork.com/news.cfm?articleID=7612
3311 # The reason seems to be an energy crisis.
3313 # From Stephen Colebourne (2007-02-22):
3314 # Some IATA info: Haiti won't be having DST in 2007.
3316 # From Steffen Thorsen (2012-03-11):
3317 # According to several news sources, Haiti will observe DST this year,
3318 # apparently using the same start and end date as USA/Canada.
3319 # So this means they have already changed their time.
3321 # http://www.alterpresse.org/spip.php?article12510
3322 # http://radiovision2000haiti.net/home/?p=13253
3324 # From Arthur David Olson (2012-03-11):
3325 # The alterpresse.org source seems to show a US-style leap from 2:00 a.m. to
3326 # 3:00 a.m. rather than the traditional Haitian jump at midnight.
3327 # Assume a US-style fall back as well.
3329 # From Steffen Thorsen (2013-03-10):
3330 # It appears that Haiti is observing DST this year as well, same rules
3331 # as US/Canada. They did it last year as well, and it looks like they
3332 # are going to observe DST every year now...
3334 # http://radiovision2000haiti.net/public/haiti-avis-changement-dheure-dimanche/
3335 # http://www.canalplushaiti.net/?p=6714
3337 # From Steffen Thorsen (2016-03-12):
3338 # Jean Antoine, editor of www.haiti-reference.com informed us that Haiti
3339 # are not going on DST this year. Several other resources confirm this: ...
3340 # https://www.radiotelevisioncaraibes.com/presse/heure_d_t_pas_de_changement_d_heure_pr_vu_pour_cet_ann_e.html
3341 # https://www.vantbefinfo.com/changement-dheure-pas-pour-haiti/
3342 # http://news.anmwe.com/haiti-lheure-nationale-ne-sera-ni-avancee-ni-reculee-cette-annee/
3344 # From Steffen Thorsen (2017-03-12):
3345 # We have received 4 mails from different people telling that Haiti
3346 # has started DST again today, and this source seems to confirm that,
3347 # I have not been able to find a more authoritative source:
3348 # https://www.haitilibre.com/en/news-20319-haiti-notices-time-change-in-haiti.html
3350 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3351 Rule Haiti 1983 only - May 8 0:00 1:00 D
3352 Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
3353 Rule Haiti 1983 1987 - Oct lastSun 0:00 0 S
3354 # Shanks & Pottenger say AT is 2:00, but IATA SSIM (1991/1997) says 1:00s.
3356 Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
3357 Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
3358 Rule Haiti 2005 2006 - Apr Sun>=1 0:00 1:00 D
3359 Rule Haiti 2005 2006 - Oct lastSun 0:00 0 S
3360 Rule Haiti 2012 2015 - Mar Sun>=8 2:00 1:00 D
3361 Rule Haiti 2012 2015 - Nov Sun>=1 2:00 0 S
3362 Rule Haiti 2017 max - Mar Sun>=8 2:00 1:00 D
3363 Rule Haiti 2017 max - Nov Sun>=1 2:00 0 S
3364 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3365 Zone America/Port-au-Prince -4:49:20 - LMT 1890
3366 -4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
3370 # Shanks & Pottenger say 1921 Jan 1; go with Whitman's more precise Apr 1.
3372 # From Paul Eggert (2006-05-05):
3373 # worldtimezone.com reports a 2006-05-02 Spanish-language AP article
3374 # saying Honduras will start using DST midnight Saturday, effective 4
3375 # months until September. La Tribuna reported today
3376 # <http://www.latribuna.hn/99299.html> that Manuel Zelaya, the president
3377 # of Honduras, refused to back down on this.
3379 # From Jesper Nørgaard Welen (2006-08-08):
3380 # It seems that Honduras has returned from DST to standard time this Monday at
3381 # 00:00 hours (prolonging Sunday to 25 hours duration).
3382 # http://www.worldtimezone.com/dst_news/dst_news_honduras04.html
3384 # From Paul Eggert (2006-08-08):
3385 # Also see Diario El Heraldo, The country returns to standard time (2006-08-08).
3386 # http://www.elheraldo.hn/nota.php?nid=54941&sec=12
3387 # It mentions executive decree 18-2006.
3389 # From Steffen Thorsen (2006-08-17):
3390 # Honduras will observe DST from 2007 to 2009, exact dates are not
3391 # published, I have located this authoritative source:
3392 # http://www.presidencia.gob.hn/noticia.aspx?nId=47
3394 # From Steffen Thorsen (2007-03-30):
3395 # http://www.laprensahn.com/pais_nota.php?id04962=7386
3396 # So it seems that Honduras will not enter DST this year....
3398 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3399 Rule Hond 1987 1988 - May Sun>=1 0:00 1:00 D
3400 Rule Hond 1987 1988 - Sep lastSun 0:00 0 S
3401 Rule Hond 2006 only - May Sun>=1 0:00 1:00 D
3402 Rule Hond 2006 only - Aug Mon>=1 0:00 0 S
3403 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3404 Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
3407 # Great Swan I ceded by US to Honduras in 1972
3410 # Shanks & Pottenger give -5:07:12, but Milne records -5:07:10.41 from an
3411 # unspecified official document, and says "This time is used throughout the
3412 # island". Go with Milne.
3414 # Shanks & Pottenger give April 28 for the 1974 spring-forward transition, but
3415 # Lance Neita writes that Prime Minister Michael Manley decreed it January 5.
3416 # Assume Neita meant Jan 6 02:00, the same as the US. Neita also writes that
3417 # Manley's supporters associated this act with Manley's nickname "Joshua"
3418 # (recall that in the Bible the sun stood still at Joshua's request),
3419 # and with the Rod of Correction which Manley said he had received from
3420 # Haile Selassie, Emperor of Ethiopia. See:
3421 # Neita L. The politician in all of us. Jamaica Observer 2014-09-20
3422 # http://www.jamaicaobserver.com/columns/The-politician-in-all-of-us_17573647
3424 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3426 Zone America/Jamaica -5:07:10 - LMT 1890 # Kingston
3427 -5:07:10 - KMT 1912 Feb # Kingston Mean Time
3433 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3434 Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
3435 -4:04:20 - FFMT 1911 May # Fort-de-France MT
3436 -4:00 - AST 1980 Apr 6
3437 -4:00 1:00 ADT 1980 Sep 28
3442 # This uses Shanks & Pottenger for times before 2005.
3444 # From Steffen Thorsen (2005-04-12):
3445 # I've got reports from 8 different people that Nicaragua just started
3446 # DST on Sunday 2005-04-10, in order to save energy because of
3447 # expensive petroleum. The exact end date for DST is not yet
3448 # announced, only "September" but some sites also say "mid-September".
3449 # Some background information is available on the President's official site:
3450 # http://www.presidencia.gob.ni/Presidencia/Files_index/Secretaria/Notas%20de%20Prensa/Presidente/2005/ABRIL/Gobierno-de-nicaragua-adelanta-hora-oficial-06abril.htm
3451 # The Decree, no 23-2005 is available here:
3452 # http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2005/Decreto%2023-2005%20Se%20adelanta%20en%20una%20hora%20en%20todo%20el%20territorio%20nacional%20apartir%20de%20las%2024horas%20del%2009%20de%20Abril.pdf
3454 # From Paul Eggert (2005-05-01):
3455 # The decree doesn't say anything about daylight saving, but for now let's
3456 # assume that it is daylight saving....
3458 # From Gwillim Law (2005-04-21):
3459 # The Associated Press story on the time change, which can be found at
3460 # http://www.lapalmainteractivo.com/guias/content/gen/ap/America_Latina/AMC_GEN_NICARAGUA_HORA.html
3461 # and elsewhere, says (fifth paragraph, translated from Spanish): "The last
3462 # time that a change of clocks was applied to save energy was in the year 2000
3463 # during the Arnoldo Alemán administration."...
3464 # The northamerica file says that Nicaragua has been on UTC-6 continuously
3465 # since December 1998. I wasn't able to find any details of Nicaraguan time
3466 # changes in 2000. Perhaps a note could be added to the northamerica file, to
3467 # the effect that we have indirect evidence that DST was observed in 2000.
3469 # From Jesper Nørgaard Welen (2005-11-02):
3470 # Nicaragua left DST the 2005-10-02 at 00:00 (local time).
3471 # http://www.presidencia.gob.ni/presidencia/files_index/secretaria/comunicados/2005/septiembre/26septiembre-cambio-hora.htm
3474 # From Jesper Nørgaard Welen (2006-05-05):
3475 # http://www.elnuevodiario.com.ni/2006/05/01/nacionales/18410
3476 # (my informal translation)
3477 # By order of the president of the republic, Enrique Bolaños, Nicaragua
3478 # advanced by sixty minutes their official time, yesterday at 2 in the
3479 # morning, and will stay that way until 30th of September.
3481 # From Jesper Nørgaard Welen (2006-09-30):
3482 # http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2006/D-063-2006P-PRN-Cambio-Hora.pdf
3483 # My informal translation runs:
3484 # The natural sun time is restored in all the national territory, in that the
3485 # time is returned one hour at 01:00 am of October 1 of 2006.
3487 # Rule NAME FROM TO - IN ON AT SAVE LETTER/S
3488 Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
3489 Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
3490 Rule Nic 2005 only - Apr 10 0:00 1:00 D
3491 Rule Nic 2005 only - Oct Sun>=1 0:00 0 S
3492 Rule Nic 2006 only - Apr 30 2:00 1:00 D
3493 Rule Nic 2006 only - Oct Sun>=1 1:00 0 S
3494 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3495 Zone America/Managua -5:45:08 - LMT 1890
3496 -5:45:12 - MMT 1934 Jun 23 # Managua Mean Time?
3497 -6:00 - CST 1973 May
3498 -5:00 - EST 1975 Feb 16
3499 -6:00 Nic C%sT 1992 Jan 1 4:00
3500 -5:00 - EST 1992 Sep 24
3508 # Atikokan and Coral Harbour, Canada, match Panama since 1970.
3509 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3510 Zone America/Panama -5:18:08 - LMT 1890
3511 -5:19:36 - CMT 1908 Apr 22 # Colón Mean Time
3517 # Caribbean Netherlands
3526 # Sint Maarten / St Martin
3528 # St Vincent & the Grenadines
3530 # Virgin Is (UK & US)
3532 # There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
3533 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3534 Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
3535 -4:00 - AST 1942 May 3
3539 # St Pierre and Miquelon
3540 # There are too many St Pierres elsewhere, so we'll use 'Miquelon'.
3541 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3542 Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
3543 -4:00 - AST 1980 May
3545 -3:00 Canada -03/-02
3549 # From Chris Dunn in
3550 # https://bugs.debian.org/415007
3551 # (2007-03-15): In the Turks & Caicos Islands (America/Grand_Turk) the
3552 # daylight saving dates for time changes have been adjusted to match
3553 # the recent U.S. change of dates.
3555 # From Brian Inglis (2007-04-28):
3556 # http://www.turksandcaicos.tc/calendar/index.htm [2007-04-26]
3557 # there is an entry for Nov 4 "Daylight Savings Time Ends 2007" and three
3558 # rows before that there is an out of date entry for Oct:
3559 # "Eastern Standard Times Begins 2007
3560 # Clocks are set back one hour at 2:00 a.m. local Daylight Saving Time"
3561 # indicating that the normal ET rules are followed.
3563 # From Paul Eggert (2014-08-19):
3564 # The 2014-08-13 Cabinet meeting decided to stay on UT -04 year-round. See:
3565 # http://tcweeklynews.com/daylight-savings-time-to-be-maintained-p5353-127.htm
3566 # Model this as a switch from EST/EDT to AST ...
3567 # From Chris Walton (2014-11-04):
3568 # ... the TCI government appears to have delayed the switch to
3569 # "permanent daylight saving time" by one year....
3570 # http://tcweeklynews.com/time-change-to-go-ahead-this-november-p5437-127.htm
3572 # From the Turks & Caicos Cabinet (2017-07-20), heads-up from Steffen Thorsen:
3573 # ... agreed to the reintroduction in TCI of Daylight Saving Time (DST)
3574 # during the summer months and Standard Time, also known as Local
3575 # Time, during the winter months with effect from April 2018 ...
3576 # https://www.gov.uk/government/news/turks-and-caicos-post-cabinet-meeting-statement--3
3577 # From Paul Eggert (2017-08-26):
3578 # The date of effect of the spring 2018 change appears to be March 11,
3579 # which makes more sense. See: Hamilton D. Time change back
3580 # by March 2018 for TCI. Magnetic Media. 2017-08-25.
3581 # http://magneticmediatv.com/2017/08/time-change-back-by-march-2018-for-tci/
3583 # From P Chan (2020-11-27):
3584 # Standard Time Declaration Order 2015 (L.N. 15/2015)
3585 # http://online.fliphtml5.com/fizd/czin/#p=2
3587 # Standard Time Declaration Order 2017 (L.N. 31/2017)
3588 # http://online.fliphtml5.com/fizd/dmcu/#p=2
3590 # From Tim Parenti (2020-12-05):
3591 # Although L.N. 31/2017 reads that it "shall come into operation at 2:00 a.m.
3592 # on 11th March 2018", a precise interpretation here poses some problems. The
3593 # order states that "the standard time to be observed throughout the Turks and
3594 # Caicos Islands shall be the same time zone as the Eastern United States of
3595 # America" and further clarifies "[f]or the avoidance of doubt" that it
3596 # "applies to the Eastern Standard Time as well as any changes thereto for
3597 # Daylight Saving Time." However, as clocks in Turks and Caicos approached
3598 # 02:00 -04, and thus the declared implementation time, it was still 01:00 EST
3599 # (-05), as DST in the Eastern US would not start until an hour later.
3601 # Since it is unlikely that those on the islands switched their clocks twice in
3602 # the span of an hour, we assume instead that the adoption of EDT actually took
3603 # effect once clocks in the Eastern US had sprung forward, from 03:00 -04.
3604 # This discrepancy only affects the time zone abbreviation and DST flag for the
3605 # intervening hour, not wall clock times, as -04 was maintained throughout.
3607 # Zone NAME STDOFF RULES FORMAT [UNTIL]
3608 Zone America/Grand_Turk -4:44:32 - LMT 1890
3610 -5:07:10 - KMT 1912 Feb # Kingston Mean Time
3612 -5:00 US E%sT 2015 Mar 8 2:00
3613 -4:00 - AST 2018 Mar 11 3:00
projects / factor.git / blob