From 2f171a25cc837cca7be0bad9c6d3ce73d52784a9 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Wed, 28 Sep 2022 20:08:31 -0700 Subject: [PATCH] Treat 1931 changes in Mexico as DST Reference: https://github.com/eggert/tz/commit/ff2e2a09a7609efb4826b1083e880cfc1913fb92 Conflict: remove NEWS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Mexico’s Chamber of Deputies was supposed to vote today on legislation abolishing DST in most of Mexico. Although the vote was delayed due to Internet problems, news coverage of the non-event led me to review our sources for DST in Mexico, and I found that tzdb considered the transitions in 1931 to be two changes to standard time, whereas it is considered to be DST in today’s news coverage, as well as in our main source, the history of Mexican local time published by the Investigation and Analysis Service of the Mexican Library of Congress. Fix this by considering the 1931 changes to be DST, not standard time. * NEWS: Mention this. * northamerica (Mexico): Add DST rules for 1931. (America/Mexico_City, America/Ojinaga, America/Chihuahua) (America/Hermosillo, America/Mazatlan, America/Bahia_Banderas): Use them. --- northamerica | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) diff --git a/northamerica b/northamerica index 0ceeeea..34ebca9 100644 --- a/northamerica +++ b/northamerica @@ -2623,6 +2623,8 @@ Zone America/Dawson -9:17:40 - LMT 1900 Aug 20 # and in addition changes all of Chihuahua to -06 with no DST. # Rule NAME FROM TO - IN ON AT SAVE LETTER/S +Rule Mexico 1931 only - May 1 23:00 1:00 D +Rule Mexico 1931 only - Oct 1 0:00 0 S Rule Mexico 1939 only - Feb 5 0:00 1:00 D Rule Mexico 1939 only - Jun 25 0:00 0 S Rule Mexico 1940 only - Dec 9 0:00 1:00 D @@ -2673,9 +2675,7 @@ Zone America/Monterrey -6:41:16 - LMT 1921 Dec 31 23:18:44 Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24 -7:00 - MST 1927 Jun 10 23:00 -6:00 - CST 1930 Nov 15 - -7:00 - MST 1931 May 1 23:00 - -6:00 - CST 1931 Oct - -7:00 - MST 1932 Apr 1 + -7:00 Mexico M%sT 1932 Apr 1 -6:00 Mexico C%sT 2001 Sep 30 2:00 -6:00 - CST 2002 Feb 20 -6:00 Mexico C%sT @@ -2686,9 +2686,7 @@ Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24 Zone America/Ojinaga -6:57:40 - LMT 1922 Jan 1 0:02:20 -7:00 - MST 1927 Jun 10 23:00 -6:00 - CST 1930 Nov 15 - -7:00 - MST 1931 May 1 23:00 - -6:00 - CST 1931 Oct - -7:00 - MST 1932 Apr 1 + -7:00 Mexico M%sT 1932 Apr 1 -6:00 - CST 1996 -6:00 Mexico C%sT 1998 -6:00 - CST 1998 Apr Sun>=1 3:00 @@ -2699,9 +2697,7 @@ Zone America/Ojinaga -6:57:40 - LMT 1922 Jan 1 0:02:20 Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:40 -7:00 - MST 1927 Jun 10 23:00 -6:00 - CST 1930 Nov 15 - -7:00 - MST 1931 May 1 23:00 - -6:00 - CST 1931 Oct - -7:00 - MST 1932 Apr 1 + -7:00 Mexico M%sT 1932 Apr 1 -6:00 - CST 1996 -6:00 Mexico C%sT 1998 -6:00 - CST 1998 Apr Sun>=1 3:00 @@ -2711,9 +2707,7 @@ Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:40 Zone America/Hermosillo -7:23:52 - LMT 1921 Dec 31 23:36:08 -7:00 - MST 1927 Jun 10 23:00 -6:00 - CST 1930 Nov 15 - -7:00 - MST 1931 May 1 23:00 - -6:00 - CST 1931 Oct - -7:00 - MST 1932 Apr 1 + -7:00 Mexico M%sT 1932 Apr 1 -6:00 - CST 1942 Apr 24 -7:00 - MST 1949 Jan 14 -8:00 - PST 1970 @@ -2751,9 +2745,7 @@ Zone America/Hermosillo -7:23:52 - LMT 1921 Dec 31 23:36:08 Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20 -7:00 - MST 1927 Jun 10 23:00 -6:00 - CST 1930 Nov 15 - -7:00 - MST 1931 May 1 23:00 - -6:00 - CST 1931 Oct - -7:00 - MST 1932 Apr 1 + -7:00 Mexico M%sT 1932 Apr 1 -6:00 - CST 1942 Apr 24 -7:00 - MST 1949 Jan 14 -8:00 - PST 1970 @@ -2763,9 +2755,7 @@ Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20 Zone America/Bahia_Banderas -7:01:00 - LMT 1921 Dec 31 23:59:00 -7:00 - MST 1927 Jun 10 23:00 -6:00 - CST 1930 Nov 15 - -7:00 - MST 1931 May 1 23:00 - -6:00 - CST 1931 Oct - -7:00 - MST 1932 Apr 1 + -7:00 Mexico M%sT 1932 Apr 1 -6:00 - CST 1942 Apr 24 -7:00 - MST 1949 Jan 14 -8:00 - PST 1970 -- 2.33.0