>From c99693f4a228e883cb0ee0d04c55b28ef817dd37 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 3 Apr 2015 17:00:07 -0700 Subject: [PROPOSED PATCH] Several changes to Chile time stamps 1890-1990 (Thanks to Alois Treindl for reporting the problem.) * southamerica (Chile, America/Santiago, Pacific/Easter): Fix several problems in the Chilean data from 1890 through 1990. * NEWS: Document this. --- NEWS | 23 ++++++++++ southamerica | 134 ++++++++++++++++++++++++++++++++--------------------------- 2 files changed, 95 insertions(+), 62 deletions(-) diff --git a/NEWS b/NEWS index 7e7bb89..35d2c10 100644 --- a/NEWS +++ b/NEWS @@ -4,6 +4,29 @@ Unreleased, experimental changes Changes affecting past time stamps + The following changes affect some pre-1991 time stamps in Chile: + + The 1910 transition was January 10, not January 1. + + The 1918 transition was September 10, not September 1. + + The UTC-4 time observed from 1932 to 1942 is now considered to be + standard time, not year-round DST. + + Santiago observed DST (UTC-3) from 1946-07-15 through 1946-08-31, + then reverted to standard time, then switched its time zone to + UTC-5 on 1947-04-01. + + Assume transitions before 1968 were at 00:00, since we have no data + saying otherwise. + + The spring 1988 transition was 1988-10-09, not 1988-10-02. + The fall 1990 transition was 1990-03-11, not 1990-03-18. + + Assume no UTC offset change for Pacific/Easter on 1890-01-01, + and omit all transitions on Pacific/Easter from 1942 through 1946 + since we have no data suggesting that they existed. + One more zone has been turned into a link, as it differed from an existing zone only for older time stamps. As usual, this change affects UTC offsets in pre-1970 time stamps only. diff --git a/southamerica b/southamerica index 77e3584..908dd6e 100644 --- a/southamerica +++ b/southamerica @@ -1098,6 +1098,60 @@ Zone America/Rio_Branco -4:31:12 - LMT 1914 # Chile +# From Paul Eggert (2015-04-03): +# Shanks & Pottenger says America/Santiago introduced standard time in +# 1890 and rounds its UTC offset to 70W40; guess that in practice this +# was the same offset as in 1916-1919. It also says Pacific/Easter +# standardized on 109W22 in 1890; assume this didn't change the clocks. +# +# Dates for America/Santiago from 1910 to 2004 are primarily from +# the following source, cited by Oscar van Vlijmen (2006-10-08): +# [1] Chile Law +# http://www.webexhibits.org/daylightsaving/chile.html +# This contains a copy of a this official table: +# Cambios en la hora oficial de Chile desde 1900 (retrieved 2008-03-30) +# http://web.archive.org/web/20080330200901/http://www.horaoficial.cl/cambio.htm +# [1] needs several corrections, though. +# +# The first set of corrections is from: +# [2] History of the Official Time of Chile +# http://www.horaoficial.cl/ing/horaof_ing.html (retrieved 2012-03-06). See: +# http://web.archive.org/web/20120306042032/http://www.horaoficial.cl/ing/horaof_ing.html +# This is an English translation of: +# Historia de la hora oficial de Chile (retrieved 2012-10-24). See: +# http://web.archive.org/web/20121024234627/http://www.horaoficial.cl/horaof.htm +# A fancier Spanish version (requiring mouse-clicking) is at: +# http://www.horaoficial.cl/historia_hora.html +# Conflicts between [1] and [2] were resolved as follows: +# +# - [1] says the 1910 transition was Jan 1, [2] says Jan 10 and cites +# Bolet��n N�� 1, Aviso N�� 1 (1910). Go with [2]. +# +# - [1] says SMT was -4:42:45, [2] says Chile's official time from +# 1916 to 1919 was -4:42:46.3, the meridian of Chile's National +# Astronomical Observatory (OAN), then located in what is now +# Quinta Normal in Santiago. Go with [2], rounding it to -4:42:46. +# +# - [1] says the 1918 transition was Sep 1, [2] says Sep 10 and cites +# Bolet��n N�� 22, Aviso N�� 129/1918 (1918-08-23). Go with [2]. +# +# - [1] does not give times for transitions; assume they occur +# at midnight mainland time, the current common practice. However, +# go with [2]'s specification of 23:00 for the 1947-05-21 transition. +# +# Another correction to [1] is from Jesper N��rgaard Welen, who +# wrote (2006-10-08), "I think that there are some obvious mistakes in +# the suggested link from Oscar van Vlijmen,... for instance entry 66 +# says that GMT-4 ended 1990-09-12 while entry 67 only begins GMT-3 at +# 1990-09-15 (they should have been 1990-09-15 and 1990-09-16 +# respectively), but anyhow it clears up some doubts too." +# +# Data for Pacific/Easter from 1910 through 1967 come from Shanks & +# Pottenger. After that, for lack of better info assume +# Pacific/Easter is always two hours behind America/Santiago; +# this is known to work for DST transitions starting in 2008 and +# may well be true for earlier transitions. + # From Eduardo Krell (1995-10-19): # The law says to switch to DST at midnight [24:00] on the second SATURDAY # of October.... The law is the same for March and October. @@ -1110,78 +1164,35 @@ Zone America/Rio_Branco -4:31:12 - LMT 1914 # Because of the same drought, the government decided to end DST later, # on April 3, (one-time change). -# From Oscar van Vlijmen (2006-10-08): -# http://www.horaoficial.cl/cambio.htm - -# From Jesper N��rgaard Welen (2006-10-08): -# I think that there are some obvious mistakes in the suggested link -# from Oscar van Vlijmen,... for instance entry 66 says that GMT-4 -# ended 1990-09-12 while entry 67 only begins GMT-3 at 1990-09-15 -# (they should have been 1990-09-15 and 1990-09-16 respectively), but -# anyhow it clears up some doubts too. - -# From Paul Eggert (2014-08-12): -# The following data entries for Chile and America/Santiago are from -# (2006-09-20), transcribed by -# Jesper N��rgaard Welen. The data entries for Pacific/Easter are from Shanks -# & Pottenger, except with DST transitions after 1932 cloned from -# America/Santiago. The pre-1980 Pacific/Easter data entries are dubious, -# but we have no other source. - # From Germ��n Poo-Caama��o (2008-03-03): # Due to drought, Chile extends Daylight Time in three weeks. This # is one-time change (Saturday 3/29 at 24:00 for America/Santiago # and Saturday 3/29 at 22:00 for Pacific/Easter) # The Supreme Decree is located at # http://www.shoa.cl/servicios/supremo316.pdf -# and the instructions for 2008 are located in: -# http://www.horaoficial.cl/cambio.htm - +# # From Jos�� Miguel Garrido (2008-03-05): -# ... -# You could see the announces of the change on # http://www.shoa.cl/noticias/2008/04hora/hora.htm # From Angel Chiang (2010-03-04): # Subject: DST in Chile exceptionally extended to 3 April due to earthquake # http://www.gobiernodechile.cl/viewNoticia.aspx?idArticulo=30098 -# (in Spanish, last paragraph). # -# This is breaking news. There should be more information available later. - # From Arthur David Olson (2010-03-06): # Angel Chiang's message confirmed by Julio Pacheco; Julio provided a patch. -# From Glenn Eychaner (2011-03-02): -# It appears that the Chilean government has decided to postpone the -# change from summer time to winter time again, by three weeks to April -# 2nd: -# http://www.emol.com/noticias/nacional/detalle/detallenoticias.asp?idnoticia=467651 -# -# This is not yet reflected in the official "cambio de hora" site, but -# probably will be soon: -# http://www.horaoficial.cl/cambio.htm - -# From Arthur David Olson (2011-03-02): -# The emol.com article mentions a water shortage as the cause of the -# postponement, which may mean that it's not a permanent change. - # From Glenn Eychaner (2011-03-28): -# The article: # http://diario.elmercurio.com/2011/03/28/_portada/_portada/noticias/7565897A-CA86-49E6-9E03-660B21A4883E.htm?id=3D{7565897A-CA86-49E6-9E03-660B21A4883E} -# # In English: # Chile's clocks will go back an hour this year on the 7th of May instead # of this Saturday. They will go forward again the 3rd Saturday in -# August, not in October as they have since 1968. This is a pilot plan -# which will be reevaluated in 2012. +# August, not in October as they have since 1968. # From Mauricio Parada (2012-02-22), translated by Glenn Eychaner (2012-02-23): # As stated in the website of the Chilean Energy Ministry # http://www.minenergia.cl/ministerio/noticias/generales/gobierno-anuncia-fechas-de-cambio-de.html # The Chilean Government has decided to postpone the entrance into winter time -# (to leave DST) from March 11 2012 to April 28th 2012. The decision has not -# been yet formalized but it will within the next days. +# (to leave DST) from March 11 2012 to April 28th 2012.... # Quote from the website communication: # # 6. For the year 2012, the dates of entry into winter time will be as follows: @@ -1218,13 +1229,8 @@ Zone America/Rio_Branco -4:31:12 - LMT 1914 # 'antarctica' file. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Chile 1927 1932 - Sep 1 0:00 1:00 S +Rule Chile 1927 1931 - Sep 1 0:00 1:00 S Rule Chile 1928 1932 - Apr 1 0:00 0 - -Rule Chile 1942 only - Jun 1 4:00u 0 - -Rule Chile 1942 only - Aug 1 5:00u 1:00 S -Rule Chile 1946 only - Jul 15 4:00u 1:00 S -Rule Chile 1946 only - Sep 1 3:00u 0:00 - -Rule Chile 1947 only - Apr 1 4:00u 0 - Rule Chile 1968 only - Nov 3 4:00u 1:00 S Rule Chile 1969 only - Mar 30 3:00u 0 - Rule Chile 1969 only - Nov 23 4:00u 1:00 S @@ -1235,10 +1241,8 @@ Rule Chile 1972 1986 - Mar Sun>=9 3:00u 0 - Rule Chile 1973 only - Sep 30 4:00u 1:00 S Rule Chile 1974 1987 - Oct Sun>=9 4:00u 1:00 S Rule Chile 1987 only - Apr 12 3:00u 0 - -Rule Chile 1988 1989 - Mar Sun>=9 3:00u 0 - -Rule Chile 1988 only - Oct Sun>=1 4:00u 1:00 S -Rule Chile 1989 only - Oct Sun>=9 4:00u 1:00 S -Rule Chile 1990 only - Mar 18 3:00u 0 - +Rule Chile 1988 1990 - Mar Sun>=9 3:00u 0 - +Rule Chile 1988 1989 - Oct Sun>=9 4:00u 1:00 S Rule Chile 1990 only - Sep 16 4:00u 1:00 S Rule Chile 1991 1996 - Mar Sun>=9 3:00u 0 - Rule Chile 1991 1997 - Oct Sun>=9 4:00u 1:00 S @@ -1261,15 +1265,21 @@ Rule Chile 2012 2014 - Sep Sun>=2 4:00u 1:00 S # (1996-09) says 1998-03-08. Ignore these. # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Santiago -4:42:46 - LMT 1890 - -4:42:46 - SMT 1910 # Santiago Mean Time + -4:42:46 - SMT 1910 Jan 10 # Santiago Mean Time -5:00 - CLT 1916 Jul 1 # Chile Time - -4:42:46 - SMT 1918 Sep 1 # Santiago Mean Time - -4:00 - CLT 1919 Jul 1 # Chile Time - -4:42:46 - SMT 1927 Sep 1 # Santiago Mean Time - -5:00 Chile CL%sT 1947 May 22 # Chile Time + -4:42:46 - SMT 1918 Sep 10 + -4:00 - CLT 1919 Jul 1 + -4:42:46 - SMT 1927 Sep 1 + -5:00 Chile CL%sT 1932 Sep 1 + -4:00 - CLT 1942 Jun 1 + -5:00 - CLT 1942 Aug 1 + -4:00 - CLT 1946 Jul 15 + -4:00 1:00 CLST 1946 Sep 1 # central Chile + -4:00 - CLT 1947 Apr 1 + -5:00 - CLT 1947 May 21 23:00 -4:00 Chile CL%sT 2015 Apr 26 3:00u -3:00 - CLT -Zone Pacific/Easter -7:17:44 - LMT 1890 +Zone Pacific/Easter -7:17:28 - LMT 1890 -7:17:28 - EMT 1932 Sep # Easter Mean Time -7:00 Chile EAS%sT 1982 Mar 14 3:00u # Easter Time -6:00 Chile EAS%sT 2015 Apr 26 3:00u -- 2.1.0