From 2cf08a797d57482558bacebad4163ad98c13eff9 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sat, 15 Oct 2022 12:44:46 -0700 Subject: [PROPOSED] Simplify four Ontario zones into one (Problem reported by Chris Walton.) * NEWS: Mention this. * backward (America/Nipigon, America/Rainy_River, America/Thunder_Bay): New backward-compatibility links. * backzone (America/Nipigon, America/Rainy_River, America/Thunder_Bay): Move data here (after correcting Thunder Bay in 1973) ... * northamerica: ... from here. * zone.tab, zone1970.tab: Remove the three zones. --- NEWS | 11 ++++++++- backward | 3 +++ backzone | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++ northamerica | 67 ++------------------------------------------------ zone.tab | 3 --- zone1970.tab | 3 --- 6 files changed, 84 insertions(+), 72 deletions(-) diff --git a/NEWS b/NEWS index a6f1f55c..d55dd799 100644 --- a/NEWS +++ b/NEWS @@ -3,7 +3,16 @@ News for the tz database Unreleased, experimental changes Briefly: - Fix a Y2438 bug when reading TZif data + Simplify four Ontario zones into one. + Fix a Y2438 bug when reading TZif data. + + Changes to past timestamps + + Simplify four Ontario zones to one, as the post-1970 differences + seem to have been imaginary. (Problem reported by Chris Walton.) + Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay + to 'backzone'; backward-compatibility links still work, albeit + with different timestamps before November 1973. Changes to code diff --git a/backward b/backward index 14e4b145..dce082de 100644 --- a/backward +++ b/backward @@ -31,10 +31,13 @@ Link America/Indiana/Knox America/Knox_IN Link America/Kentucky/Louisville America/Louisville Link America/Argentina/Mendoza America/Mendoza Link America/Toronto America/Montreal +Link America/Toronto America/Nipigon Link America/Rio_Branco America/Porto_Acre +Link America/Toronto America/Rainy_River Link America/Argentina/Cordoba America/Rosario Link America/Tijuana America/Santa_Isabel Link America/Denver America/Shiprock +Link America/Toronto America/Thunder_Bay Link America/Puerto_Rico America/Virgin Link Pacific/Auckland Antarctica/South_Pole Link Asia/Ashgabat Asia/Ashkhabad diff --git a/backzone b/backzone index f623f091..b4ebd2e4 100644 --- a/backzone +++ b/backzone @@ -739,6 +739,17 @@ Zone America/Nassau -5:09:30 - LMT 1912 Mar 2 -5:00 Bahamas E%sT 1976 -5:00 US E%sT +# Canada +# From Chris Walton (2022-10-15): +# I would also like to see America/Nipigon and America/Rainy_River converted +# into link entries because I have zero faith in the current Shanks based data. +# From Paul Eggert (2022-10-15): +# These are now links in the primary data. Also see America/Thunder_Bay. +Zone America/Nipigon -5:53:04 - LMT 1895 + -5:00 Canada E%sT 1940 Sep 29 + -5:00 1:00 EDT 1942 Feb 9 2:00s + -5:00 Canada E%sT + # United States # # From Paul Eggert (2018-03-18): @@ -769,6 +780,17 @@ Zone America/Port_of_Spain -4:06:04 - LMT 1912 Mar 2 Link America/Port_of_Spain America/Marigot Link America/Port_of_Spain America/St_Barthelemy +# Canada +# From Chris Walton (2022-10-15): +# I would also like to see America/Nipigon and America/Rainy_River converted +# into link entries because I have zero faith in the current Shanks based data. +# From Paul Eggert (2022-10-15): +# These are now links in the primary data. Also see America/Thunder_Bay. +Zone America/Rainy_River -6:18:16 - LMT 1895 + -6:00 Canada C%sT 1940 Sep 29 + -6:00 1:00 CDT 1942 Feb 9 2:00s + -6:00 Canada C%sT + # Argentina # This entry was intended for the following areas, but has been superseded by # more detailed zones. @@ -802,6 +824,53 @@ Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown -4:04:56 - KMT 1912 # Kingstown Mean Time -4:00 - AST +# Canada +# +# From Paul Eggert (2003-07-27): +# Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and +# Port Arthur, Ontario, the principle of the Bill has been in +# operation for the past three years, and in the City of Moose Jaw, +# Saskatchewan, for one year." +# +# From David Bryan via Tory Tronrud, Director/Curator, +# Thunder Bay Museum (2003-11-12): +# There is some suggestion, however, that, by-law or not, daylight +# savings time was being practiced in Fort William and Port Arthur +# before 1909.... [I]n 1910, the line between the Eastern and Central +# Time Zones was permanently moved about two hundred miles west to +# include the Thunder Bay area.... When Canada adopted daylight +# savings time in 1916, Fort William and Port Arthur, having done so +# already, did not change their clocks.... During the Second World +# War,... [t]he cities agreed to implement DST during the summer +# months for the remainder of the war years. +# +# From Jeffery Nichols (2020-02-06): +# According to the [Shanks] atlas, those western Ontario zones are huge, +# covering most of Ontario northwest of Sault Ste Marie and Timmins. +# The zones seem to include towns bigger than the ones they're named after, +# like Dryden in America/Rainy_River and Wawa (and maybe Attawapiskat) in +# America/Nipigon. I assume it's too much trouble to change the name of the +# zone (like when you found out that America/Glace_Bay includes Sydney, Nova +# Scotia).... +# +# From Chris Walton (2022-10-15): +# The TZ database currently shows that Thunder Bay has observed daylight +# saving every year from 1970 onwards with the exception of 1973. +# Back in July I raised some doubts on this mailing list about the 1973 data. +# I now have more proof that it is wrong. +# [attached Chronicle-Journal front pages, 1973-04-28 and 1973-10-27] +# +# From Paul Eggert (2022-10-15): +# This is now a link in the primary data. The following entry is +# from Shanks & Pottenger, with corrections as noted above. +# +Zone America/Thunder_Bay -5:57:00 - LMT 1895 + -6:00 - CST 1910 + -5:00 - EST 1942 + -5:00 Canada E%sT 1970 + -5:00 Toronto E%sT 1974 + -5:00 Canada E%sT + # British Virgin Is Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town -4:00 - AST diff --git a/northamerica b/northamerica index da84f354..10419153 100644 --- a/northamerica +++ b/northamerica @@ -1603,23 +1603,6 @@ Zone America/Moncton -4:19:08 - LMT 1883 Dec 9 # Ontario -# From Paul Eggert (2006-07-09): -# Shanks & Pottenger write that since 1970 most of Ontario has been like -# Toronto. -# Thunder Bay skipped DST in 1973. -# Many smaller locales did not observe peacetime DST until 1974; -# Nipigon (EST) and Rainy River (CST) are the largest that we know of. -# Far west Ontario is like Winnipeg; far east Quebec is like Halifax. - -# From Jeffery Nichols (2020-02-06): -# According to the [Shanks] atlas, those western Ontario zones are huge, -# covering most of Ontario northwest of Sault Ste Marie and Timmins. -# The zones seem to include towns bigger than the ones they're named after, -# like Dryden in America/Rainy_River and Wawa (and maybe Attawapiskat) in -# America/Nipigon. I assume it's too much trouble to change the name of the -# zone (like when you found out that America/Glace_Bay includes Sydney, Nova -# Scotia).... - # From Mark Brader (2003-07-26): # [According to the Toronto Star] Orillia, Ontario, adopted DST # effective Saturday, 1912-06-22, 22:00; the article mentions that @@ -1640,17 +1623,6 @@ Zone America/Moncton -4:19:08 - LMT 1883 Dec 9 # From Mark Brader (2010-03-06): # -# Currently the database has: -# -# # Ontario -# -# # From Paul Eggert (2006-07-09): -# # Shanks & Pottenger write that since 1970 most of Ontario has been like -# # Toronto. -# # Thunder Bay skipped DST in 1973. -# # Many smaller locales did not observe peacetime DST until 1974; -# # Nipigon (EST) and Rainy River (CST) are the largest that we know of. -# # In the (Toronto) Globe and Mail for Saturday, 1955-09-24, in the bottom # right corner of page 1, it says that Toronto will return to standard # time at 2 am Sunday morning (which agrees with the database), and that: @@ -1658,10 +1630,8 @@ Zone America/Moncton -4:19:08 - LMT 1883 Dec 9 # The one-hour setback will go into effect throughout most of Ontario, # except in areas like Windsor which remains on standard time all year. # -# Windsor is, of course, a lot larger than Nipigon. -# -# I only came across this incidentally. I don't know if Windsor began -# observing DST when Detroit did, or in 1974, or on some other date. +# ... I don't know if Windsor began observing DST when Detroit did, +# or in 1974, or on some other date. # # By the way, the article continues by noting that: # @@ -1743,24 +1713,6 @@ Rule Toronto 1951 1956 - Sep lastSun 2:00 0 S # Toronto Star, which said that DST was ending 1971-10-31 as usual. Rule Toronto 1957 1973 - Oct lastSun 2:00 0 S -# From Paul Eggert (2003-07-27): -# Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and -# Port Arthur, Ontario, the principle of the Bill has been in -# operation for the past three years, and in the City of Moose Jaw, -# Saskatchewan, for one year." - -# From David Bryan via Tory Tronrud, Director/Curator, -# Thunder Bay Museum (2003-11-12): -# There is some suggestion, however, that, by-law or not, daylight -# savings time was being practiced in Fort William and Port Arthur -# before 1909.... [I]n 1910, the line between the Eastern and Central -# Time Zones was permanently moved about two hundred miles west to -# include the Thunder Bay area.... When Canada adopted daylight -# savings time in 1916, Fort William and Port Arthur, having done so -# already, did not change their clocks.... During the Second World -# War,... [t]he cities agreed to implement DST during the summer -# months for the remainder of the war years. - # Zone NAME STDOFF RULES FORMAT [UNTIL] Zone America/Toronto -5:17:32 - LMT 1895 -5:00 Canada E%sT 1919 @@ -1769,21 +1721,6 @@ Zone America/Toronto -5:17:32 - LMT 1895 -5:00 Toronto E%sT 1974 -5:00 Canada E%sT Link America/Toronto America/Nassau -Zone America/Thunder_Bay -5:57:00 - LMT 1895 - -6:00 - CST 1910 - -5:00 - EST 1942 - -5:00 Canada E%sT 1970 - -5:00 Toronto E%sT 1973 - -5:00 - EST 1974 - -5:00 Canada E%sT -Zone America/Nipigon -5:53:04 - LMT 1895 - -5:00 Canada E%sT 1940 Sep 29 - -5:00 1:00 EDT 1942 Feb 9 2:00s - -5:00 Canada E%sT -Zone America/Rainy_River -6:18:16 - LMT 1895 - -6:00 Canada C%sT 1940 Sep 29 - -6:00 1:00 CDT 1942 Feb 9 2:00s - -6:00 Canada C%sT # For Atikokan see America/Panama. diff --git a/zone.tab b/zone.tab index 49040289..2636e21a 100644 --- a/zone.tab +++ b/zone.tab @@ -114,13 +114,10 @@ CA +4606-06447 America/Moncton Atlantic - New Brunswick CA +5320-06025 America/Goose_Bay Atlantic - Labrador (most areas) CA +5125-05707 America/Blanc-Sablon AST - QC (Lower North Shore) CA +4339-07923 America/Toronto Eastern - ON, QC (most areas) -CA +4901-08816 America/Nipigon Eastern - ON, QC (no DST 1967-73) -CA +4823-08915 America/Thunder_Bay Eastern - ON (Thunder Bay) CA +6344-06828 America/Iqaluit Eastern - NU (most east areas) CA +6608-06544 America/Pangnirtung Eastern - NU (Pangnirtung) CA +484531-0913718 America/Atikokan EST - ON (Atikokan); NU (Coral H) CA +4953-09709 America/Winnipeg Central - ON (west); Manitoba -CA +4843-09434 America/Rainy_River Central - ON (Rainy R, Ft Frances) CA +744144-0944945 America/Resolute Central - NU (Resolute) CA +624900-0920459 America/Rankin_Inlet Central - NU (central) CA +5024-10439 America/Regina CST - SK (most areas) diff --git a/zone1970.tab b/zone1970.tab index cf9cf201..75372e3f 100644 --- a/zone1970.tab +++ b/zone1970.tab @@ -102,12 +102,9 @@ CA +4612-05957 America/Glace_Bay Atlantic - NS (Cape Breton) CA +4606-06447 America/Moncton Atlantic - New Brunswick CA +5320-06025 America/Goose_Bay Atlantic - Labrador (most areas) CA,BS +4339-07923 America/Toronto Eastern - ON, QC (most areas), Bahamas -CA +4901-08816 America/Nipigon Eastern - ON, QC (no DST 1967-73) -CA +4823-08915 America/Thunder_Bay Eastern - ON (Thunder Bay) CA +6344-06828 America/Iqaluit Eastern - NU (most east areas) CA +6608-06544 America/Pangnirtung Eastern - NU (Pangnirtung) CA +4953-09709 America/Winnipeg Central - ON (west); Manitoba -CA +4843-09434 America/Rainy_River Central - ON (Rainy R, Ft Frances) CA +744144-0944945 America/Resolute Central - NU (Resolute) CA +624900-0920459 America/Rankin_Inlet Central - NU (central) CA +5024-10439 America/Regina CST - SK (most areas) -- 2.34.1