From 03eafae53a8ed5914ea2213a157529c2bd634f23 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sat, 4 Oct 2014 17:14:56 -0700 Subject: [PROPOSED PATCH 2/2] Many corrections to data for Vietnam, 1906-1975. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * asia (Asia/Ho_Chi_Minh): Rewrite the data from 1906 through 1975, using new information from Trần Tiến Bình's book. (Thanks to Trần Ngọc Quân.) New abbreviation IDT for UT+8 in Indochina. * checktab.awk (tztab): Remove special cases for this zone. * zone1970.tab: Add Asia/Ho_Chi_Minh, and add Asia/Bangkok commentary. * NEWS: Document this. --- NEWS | 8 ++++++++ asia | 51 +++++++++++++++++++++++++++++++++++++++++++-------- checktab.awk | 1 - zone1970.tab | 3 ++- 4 files changed, 53 insertions(+), 10 deletions(-) diff --git a/NEWS b/NEWS index ceadacd..f4d7942 100644 --- a/NEWS +++ b/NEWS @@ -4,6 +4,14 @@ Unreleased, experimental changes Changes affecting past time stamps + Many time stamps have been corrected for Asia/Ho_Chi_Minh before 1976 + (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's + authoritative book). Asia/Ho_Chi_Minh has been added to + zone1970.tab, to give tzselect users in Vietnam two choices, + since north and south Vietnam disagreed after our 1970 cutoff. + The new abbreviation IDT stands for the pre-1976 use of UT+8 in + Indochina, to distinguish it better from ICT (UT+7). + Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as they differed from existing zones only for older time stamps. As usual, these changes affect pre-1970 time stamps only. Their old diff --git a/asia b/asia index ea03e3f..851e6f8 100644 --- a/asia +++ b/asia @@ -47,10 +47,11 @@ # 3:30 IRST IRDT Iran # 4:00 GST Gulf* # 5:30 IST India -# 7:00 ICT Indochina* +# 7:00 ICT Indochina, most times and locations* # 7:00 WIB west Indonesia (Waktu Indonesia Barat) # 8:00 WITA central Indonesia (Waktu Indonesia Tengah) # 8:00 CST China +# 8:00 IDT Indochina, 1943-45, 1947-55, 1960-75 (some locations)* # 8:00 JWST Western Standard Time (Japan, 1896/1937)* # 9:00 JCST Central Standard Time (Japan, 1896/1937) # 9:00 WIT east Indonesia (Waktu Indonesia Timur) @@ -2763,22 +2764,56 @@ Zone Asia/Tashkent 4:37:11 - LMT 1924 May 2 # Vietnam -# From Paul Eggert (2013-02-21): +# From Paul Eggert (2014-10-04): # Milne gives 7:16:56 for the meridian of Saigon in 1899, as being # used in Lower Laos, Cambodia, and Annam. But this is quite a ways # from Saigon's location. For now, ignore this and stick with Shanks -# and Pottenger. +# and Pottenger for LMT before 1906. # From Arthur David Olson (2008-03-18): # The English-language name of Vietnam's most populous city is "Ho Chi Minh # City"; use Ho_Chi_Minh below to avoid a name of more than 14 characters. -# From Shanks & Pottenger: +# From Paul Eggert (2014-10-04) after a heads-up from Trần Ngọc Quân: +# http://www.thoigian.com.vn/?mPage=P80D01 +# lists helpful info, translated by Brian Inglis in: +# http://mm.icann.org/pipermail/tz/2014-October/021654.html +# The info cites an authoritative book by Trần Tiến Bình; a 2014 edition is +# "Lịch Việt Nam: thế kỉ XX-XXI (1901-2100) & niên biểu lịch sử Việt Nam" +# http://bookaholic.vn/lich-viet-nam-the-ki-xx-xxi-1901-2100-va-bien-bieu-lich-su-viet-nam/ +# I have asked my library for its copy of the book (a 2005 edition) +# and plan to check that. In the meantime the summary in Thời gian is much +# better than Shanks, and is the basis for the following info. +# +# The 1906 transition was effective July 1 and standardized Indochina to +# Phù Liễn Observatory, legally 104 deg. 17'17" east of Paris. +# It's unclear whether this meant legal Paris Mean Time (00:09:21) or +# the Paris Meridian (2 deg. 20'14.03" E); the former yields 07:06:30.1333... +# and the latter 07:06:29.333... so either way it rounds to 07:06:30, +# which is used below even though the modern-day Phù Liễn Observatory +# is closer to 07:06:31. Abbreviate Phù Liễn Mean Time as PLMT. +# +# The following transitions occurred in Indochina in general (before 1954) +# and in South Vietnam in particular (after 1954): +# To 07:00 on 1911-05-01. +# To 08:00 on 1942-12-31 at 23:00. +# To 09:00 in 1945-03-14 at 23:00. +# To 07:00 on 1945-09-02 in Vietnam. +# To 08:00 on 1947-04-01 in French-controlled Indochina. +# To 07:00 on 1955-07-01 in South Vietnam. +# To 08:00 on 1959-12-31 at 23:00 in South Vietnam. +# To 07:00 on 1975-06-13 in South Vietnam. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Ho_Chi_Minh 7:06:40 - LMT 1906 Jun 9 - 7:06:20 - SMT 1911 Mar 11 0:01 # Saigon MT? - 7:00 - ICT 1912 May - 8:00 - ICT 1931 May +Zone Asia/Ho_Chi_Minh 7:06:40 - LMT 1906 Jul 1 + 7:06:30 - PLMT 1911 May 1 + 7:00 - ICT 1942 Dec 31 23:00 + 8:00 - IDT 1945 Mar 14 23:00 + 9:00 - JST 1945 Sep 2 + 7:00 - ICT 1947 Apr 1 + 8:00 - IDT 1955 Jul 1 + 7:00 - ICT 1959 Dec 31 23:00 + 8:00 - IDT 1975 Jun 13 7:00 - ICT # Yemen diff --git a/checktab.awk b/checktab.awk index 3da1e9b..55baa54 100644 --- a/checktab.awk +++ b/checktab.awk @@ -25,7 +25,6 @@ BEGIN { tztab["America/Cayman"] = 1 tztab["Asia/Aden"] = 1 tztab["Asia/Bahrain"] = 1 - tztab["Asia/Ho_Chi_Minh"] = 1 tztab["Asia/Kuwait"] = 1 tztab["Asia/Muscat"] = 1 tztab["Indian/Antananarivo"] = 1 diff --git a/zone1970.tab b/zone1970.tab index f0e38f1..57c11f1 100644 --- a/zone1970.tab +++ b/zone1970.tab @@ -315,7 +315,7 @@ SY +3330+03618 Asia/Damascus TC +2128-07108 America/Grand_Turk TD +1207+01503 Africa/Ndjamena TF -492110+0701303 Indian/Kerguelen Kerguelen, St Paul I, Amsterdam I -TH,KH,LA,VN +1345+10031 Asia/Bangkok +TH,KH,LA,VN +1345+10031 Asia/Bangkok most of Indochina TJ +3835+06848 Asia/Dushanbe TK -0922-17114 Pacific/Fakaofo TL -0833+12535 Asia/Dili @@ -363,6 +363,7 @@ UY -3453-05611 America/Montevideo UZ +3940+06648 Asia/Samarkand west Uzbekistan UZ +4120+06918 Asia/Tashkent east Uzbekistan VE +1030-06656 America/Caracas +VN +1045+10640 Asia/Ho_Chi_Minh south Vietnam VU -1740+16825 Pacific/Efate WF -1318-17610 Pacific/Wallis WS -1350-17144 Pacific/Apia -- 1.9.1