[tz] [PATCH] tzdata: Asia/Ha_Noi: Add new timezone
Paul Eggert
eggert at cs.ucla.edu
Sun Oct 5 00:32:06 UTC 2014
Tim Parenti wrote:
> ... ICT referring to different UT offsets for several periods. Perhaps, prior to
> reunification, NICT and SICT should be used for "North/South Indochina Time"?
It wasn't North vs South. The new data say that French Indochina mostly used
UT+7, but sometimes all of French Indochina used UT+8, sometimes just South
Vietnam, sometimes more of a hodgepodge. I had independently run into this
problem and thought of using the abbreviation "IDT" (short for InDochina Time)
for UT+8 in Indochina to help clear this up.
There's a bigger problem, though. The new data also tell us that our entries
for Laos and Cambodia are almost entirely bogus. We already knew that, and I
had slated them for 'backzone' anyway, so now's a good time to do that. As a
corollary, although we clearly need to fix Asia/Ho_Chi_Minh, we don't need a
separate Zone for Asia/Hanoi as it is identical to Asia/Bangkok since 1970.
This will give us a simpler fix and an easier-to-maintain result.
A proposed pair of patches is attached. The first moves the bogus data for
Cambodia and Laos to 'backzone'. The second fixes Asia/Ho_Chi_Minh and adds a
line to zone1970.tab so that users in Vietnam now have two choices, one for each
half of the country.
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From 6f7ddecfb036e13a1132181cfaa8ab3e070fc9e8 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
Date: Sat, 4 Oct 2014 16:54:39 -0700
Subject: [PROPOSED PATCH 1/2] Move two out-of-scope Indochina zones to
'backzone'.
* asia (Asia/Phnom_Penh, Asia/Vientiane):
Change these from zones to links to Asia/Bangkok.
* backzone: Move the old data here.
* checktab.awk (tztab): Remove special cases for these zones.
* NEWS: Document the above.
---
NEWS | 7 +++++++
asia | 18 ++++++------------
backzone | 14 ++++++++++++++
checktab.awk | 2 --
4 files changed, 27 insertions(+), 14 deletions(-)
diff --git a/NEWS b/NEWS
index eccb0ed..ceadacd 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,13 @@ News for the tz database
Unreleased, experimental changes
+ Changes affecting past time stamps
+
+ 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
+ contents have been moved to the 'backzone' file.
+
Changes affecting code
If USG_COMPAT is defined and the requested time stamp is standard time,
diff --git a/asia b/asia
index 0be896b..ea03e3f 100644
--- a/asia
+++ b/asia
@@ -271,12 +271,8 @@ Zone Asia/Rangoon 6:24:40 - LMT 1880 # or Yangon
6:30 - MMT # Myanmar Time
# Cambodia
-# Zone NAME GMTOFF RULES FORMAT [UNTIL]
-Zone Asia/Phnom_Penh 6:59:40 - 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
- 7:00 - ICT
+# See Asia/Bangkok.
+
# China
@@ -1714,12 +1710,8 @@ Zone Asia/Kuwait 3:11:56 - LMT 1950
3:00 - AST
# Laos
-# Zone NAME GMTOFF RULES FORMAT [UNTIL]
-Zone Asia/Vientiane 6:50:24 - LMT 1906 Jun 9 # or Viangchan
- 7:06:20 - SMT 1911 Mar 11 0:01 # Saigon MT?
- 7:00 - ICT 1912 May
- 8:00 - ICT 1931 May
- 7:00 - ICT
+# See Asia/Bangkok.
+
# Lebanon
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
@@ -2732,6 +2724,8 @@ Zone Asia/Dushanbe 4:35:12 - LMT 1924 May 2
Zone Asia/Bangkok 6:42:04 - LMT 1880
6:42:04 - BMT 1920 Apr # Bangkok Mean Time
7:00 - ICT
+Link Asia/Bangkok Asia/Phnom_Penh # Cambodia
+Link Asia/Bangkok Asia/Vientiane # Laos
# Turkmenistan
# From Shanks & Pottenger.
diff --git a/backzone b/backzone
index f464131..7bb79f3 100644
--- a/backzone
+++ b/backzone
@@ -353,11 +353,25 @@ Zone Asia/Kashgar 5:03:56 - LMT 1928 # or Kashi or Kaxgar
# Portuguese India switched to GMT+5 on 1912-01-01.
#Zone Asia/Panaji [not enough info to complete]
+# Cambodia
+Zone Asia/Phnom_Penh 6:59:40 - 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
+ 7:00 - ICT
+
# Israel
Zone Asia/Tel_Aviv 2:19:04 - LMT 1880
2:21 - JMT 1918
2:00 Zion I%sT
+# Laos
+Zone Asia/Vientiane 6:50:24 - LMT 1906 Jun 9 # or Viangchan
+ 7:06:20 - SMT 1911 Mar 11 0:01 # Saigon MT?
+ 7:00 - ICT 1912 May
+ 8:00 - ICT 1931 May
+ 7:00 - ICT
+
# Jan Mayen
# From Whitman:
Zone Atlantic/Jan_Mayen -1:00 - EGT
diff --git a/checktab.awk b/checktab.awk
index 84c49ff..3da1e9b 100644
--- a/checktab.awk
+++ b/checktab.awk
@@ -28,8 +28,6 @@ BEGIN {
tztab["Asia/Ho_Chi_Minh"] = 1
tztab["Asia/Kuwait"] = 1
tztab["Asia/Muscat"] = 1
- tztab["Asia/Phnom_Penh"] = 1
- tztab["Asia/Vientiane"] = 1
tztab["Indian/Antananarivo"] = 1
tztab["Indian/Comoro"] = 1
tztab["Indian/Mayotte"] = 1
--
1.9.1
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From 03eafae53a8ed5914ea2213a157529c2bd634f23 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
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
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