+
+{ "00" } [ 2022 1 1 <date> "%U" strftime ] unit-test
+{ "01" } [ 2022 1 2 <date> "%U" strftime ] unit-test
+{ "01" } [ 2022 1 3 <date> "%U" strftime ] unit-test
+
+{ "00" } [ 2022 1 1 <date> "%W" strftime ] unit-test
+{ "00" } [ 2022 1 2 <date> "%W" strftime ] unit-test
+{ "01" } [ 2022 1 3 <date> "%W" strftime ] unit-test
+
+{ "34" } [ 2022 8 27 <date> "%U" strftime ] unit-test
+{ "35" } [ 2022 8 28 <date> "%U" strftime ] unit-test
+{ "35" } [ 2022 8 29 <date> "%U" strftime ] unit-test
+
+{ "34" } [ 2022 8 27 <date> "%W" strftime ] unit-test
+{ "34" } [ 2022 8 28 <date> "%W" strftime ] unit-test
+{ "35" } [ 2022 8 29 <date> "%W" strftime ] unit-test