Manitoba, Ontario, P.E.I., Quebec adopt 2007 US DST change
eggert at CS.UCLA.EDU
Wed Dec 21 21:25:40 UTC 2005
I looked around for news reports of the effect on the US's 2007
daylight-saving plans on Canada, and found reports that Manitoba,
Ontario, P.E.I., and Quebec are committed to switching, and other
provinces are thinking of switching.
My assumption is that all of Canada (save perhaps Newfoundland) will
switch, but that it's too early to regard this as official.
One problem is how to reflect this in the tz database. I'm inclined
to propose something along the following lines, at least for now, to
keep the tables simple; we should be able to fix things before 2007 if
some of the provinces decline to follow the US lead. Please see the
changes in commentary below to see what provinces would be affected.
RCS file: RCS/northamerica,v
retrieving revision 2005.15.1.3
diff -pu -r2005.15.1.3 northamerica
--- northamerica 2005/12/20 15:04:00 2005.15.1.3
+++ northamerica 2005/12/21 21:00:48
@@ -820,18 +820,37 @@ Zone America/Menominee -5:50:27 - LMT 18
# Unless otherwise specified, the data for Canada are all from Shanks.
-# From Paul Eggert (2000-10-02):
+# From Paul Eggert (2005-12-21):
# H. David Matthews and Mary Vincent's map
-# <a href="http://www.canadiangeographic.ca/SO98/geomap.htm">
+# <a href="http://www.canadiangeographic.ca/Magazine/SO98/geomap.asp">
# "It's about TIME", _Canadian Geographic_ (September-October 1998)
# </a> contains detailed boundaries for regions observing nonstandard
# time and daylight saving time arrangements in Canada circa 1998.
-# INMS, the Institute for National Measurement Standards in Ottawa, has
-# <a href="http://www.nrc.ca/inms/time/tze.html">
+# INMS, the Institute for National Measurement Standards in Ottawa, has <a
# information about standard and daylight saving time zones in Canada.
# </a> (updated periodically).
# Its unofficial information is often taken from Matthews and Vincent.
+# CBC News reported that Ontario and Manitoba have announced plans to
+# follow the US change, and that Nova Scotia is considering it; see
+# <http://www.cbc.ca/news/background/daylightsavingtime/> (2005-10-21).
+# CBC news also reported that Prince Edward Island is the first
+# province in Atlantic Canada to follow the US change, and that Quebec
+# had agreed; see <http://www.cbc.ca/pei/story/pe_daylight_20051207.html>
+# To reflect all this, the Canada and Winn rules have been adjusted to
+# agree with the 2007 US change. This means we assume most of Canada
+# will fall into line. However, Alberta, British Columbia,
+# Newfoundland, Northwest Territories, and Yukon already have separate
+# rules in our database, so for now we'll leave them alone, which
+# means that we currently assume these regions will not change their
+# rules and will disagree with the US starting in 2007. This
+# assumption is probably incorrect, with the possible exception of
+# Newfoundland. We plan to adjust the Edm, Vanc, StJohns, and NT_YK
+# rules as the corresponding provinces make their announcements.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Canada 1918 only - Apr 14 2:00 1:00 D
@@ -840,8 +859,10 @@ Rule Canada 1942 only - Feb 9 2:00 1:00
Rule Canada 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Canada 1945 only - Sep 30 2:00 0 S
Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
-Rule Canada 1974 max - Oct lastSun 2:00 0 S
-Rule Canada 1987 max - Apr Sun>=1 2:00 1:00 D
+Rule Canada 1974 2006 - Oct lastSun 2:00 0 S
+Rule Canada 1987 2006 - Apr Sun>=1 2:00 1:00 D
+Rule Canada 2007 max - Mar Sun>=8 2:00 1:00 D
+Rule Canada 2007 max - Nov Sun>=1 2:00 0 S
# Newfoundland (and far southeast Labrador)
@@ -1167,11 +1188,13 @@ Rule Winn 1963 only - Apr lastSun 2:00 1
Rule Winn 1963 only - Sep 22 2:00 0 S
Rule Winn 1966 1986 - Apr lastSun 2:00 1:00 D
Rule Winn 1966 1986 - Oct lastSun 2:00 0 S
-Rule Winn 1987 max - Apr Sun>=1 2:00 1:00 D
+Rule Winn 1987 2006 - Apr Sun>=1 2:00s 1:00 D
# From Paul Eggert (2000-10-02):
# INMS (2000-09-12) says that, since 1988 at least, Manitoba switches from
# DST at 03:00 local time. For now, assume it started in 1987.
-Rule Winn 1987 max - Oct lastSun 2:00s 0 S
+Rule Winn 1987 2006 - Oct lastSun 2:00s 0 S
+Rule Winn 2007 max - Mar Sun>=8 2:00s 1:00 D
+Rule Winn 2007 max - Nov Sun>=1 2:00s 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
-6:00 Winn C%sT
More information about the tz