calendar: simplify am/pm.

diff --git a/basis/calendar/calendar.factor b/basis/calendar/calendar.factor
index b791e0a0fa90457add8055ba1d6b91b1d869b381..a95baf990ec0c2711e80b28b0d95457824132e08 100644 (file)
--- a/basis/calendar/calendar.factor
+++ b/basis/calendar/calendar.factor
@@ -768,10 +768,10 @@ CONSTANT: weekday-offsets { 0 0 1 2 3 4 5 }
     [ midnight ] dip >>hour ;
 
 : am ( timestamp n -- timestamp )
-    1 12 [a,b] check-interval dup 12 = [ drop 0 ] when o'clock ;
+    1 12 [a,b] check-interval 12 mod o'clock ;
 
 : pm ( timestamp n -- timestamp )
-    1 12 [a,b] check-interval dup 12 = [ drop 0 ] when 12 + o'clock ;
+    1 12 [a,b] check-interval 12 mod 12 + o'clock ;
 
 : time-since-midnight ( timestamp -- duration )
     instant swap >time< set-time ;