Print this page
5722 Update timezone info db to 2015a

@@ -4,25 +4,24 @@
 # This file is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
-# From Paul Eggert (2013-08-11):
+# From Paul Eggert (2014-10-31):
 #
-# A good source for time zone historical data outside the U.S. is
+# Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
 # San Diego: ACS Publications, Inc. (2003).
+# Unfortunately this book contains many errors and cites no sources.
 #
 # Gwillim Law writes that a good source
 # for recent time zone data is the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
-# of the IATA's data after 1990.
+# of the IATA's data after 1990.  Except where otherwise noted,
+# IATA SSIM is the source for entries after 1990.
 #
-# Except where otherwise noted, Shanks & Pottenger is the source for
-# entries through 1990, and IATA SSIM is the source for entries afterwards.
-#
 # Another source occasionally used is Edward W. Whitman, World Time Differences,
 # Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
 # I found in the UCLA library.
 #
 # For data circa 1899, a common source is:

@@ -45,14 +44,15 @@
 #       2:00 IST  IDT   Israel
 #       3:00 AST  ADT   Arabia*
 #       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)
 #       9:00 JST  JDT   Japan
 #       9:00 KST  KDT   Korea

@@ -143,14 +143,11 @@
                         4:00    -       AZT     1996     # Azerbaijan Time
                         4:00    EUAsia  AZ%sT   1997
                         4:00    Azer    AZ%sT
 
 # Bahrain
-# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
-Zone    Asia/Bahrain    3:22:20 -       LMT     1920     # Manamah
-                        4:00    -       GST     1972 Jun
-                        3:00    -       AST
+# See Asia/Qatar.
 
 # Bangladesh
 # From Alexander Krivenyshev (2009-05-13):
 # According to newspaper Asian Tribune (May 6, 2009) Bangladesh may introduce
 # Daylight Saving Time from June 16 to Sept 30

@@ -269,17 +266,13 @@
                         6:30    -       BURT    1942 May    # Burma Time
                         9:00    -       JST     1945 May  3
                         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
 
 # From Guy Harris:
 # People's Republic of China.  Yes, they really have only one time zone.
 

@@ -891,10 +884,14 @@
 #       Lakshadweep (Laccadive, Minicoy and Amindivi Is)
 #       Nicobar Is
 
 # Indonesia
 #
+# From Paul Eggert (2014-09-06):
+# The 1876 Report of the Secretary of the [US] Navy, p 306 says that Batavia
+# civil time was 7:07:12.5; round to even for Jakarta.
+#
 # From Gwillim Law (2001-05-28), overriding Shanks & Pottenger:
 # http://www.sumatera-inc.com/go_to_invest/about_indonesia.asp#standtime
 # says that Indonesia's time zones changed on 1988-01-01.  Looking at some
 # time zone maps, I think that must refer to Western Borneo (Kalimantan Barat
 # and Kalimantan Tengah) switching from UTC+8 to UTC+7.

@@ -1660,65 +1657,85 @@
 ###############################################################################
 
 # Korea (North and South)
 
 # From Annie I. Bang (2006-07-10):
-# http://www.koreaherald.co.kr/SITE/data/html_dir/2006/07/10/200607100012.asp
-# The Ministry of Commerce, Industry and Energy has already
-# commissioned a research project [to reintroduce DST] and has said
-# the system may begin as early as 2008....  Korea ran a daylight
-# saving program from 1949-61 but stopped it during the 1950-53 Korean War.
+# http://www.koreaherald.com/view.php?ud=200607100012
+# Korea ran a daylight saving program from 1949-61 but stopped it
+# during the 1950-53 Korean War.  The system was temporarily enforced
+# between 1987 and 1988 ...
 
-# From Shanks & Pottenger:
+# From Sanghyuk Jung (2014-10-29):
+# http://mm.icann.org/pipermail/tz/2014-October/021830.html
+# According to the Korean Wikipedia
+# http://ko.wikipedia.org/wiki/한국_표준시
+# [oldid=12896437 2014-09-04 08:03 UTC]
+# DST in Republic of Korea was as follows....  And I checked old
+# newspapers in Korean, all articles correspond with data in Wikipedia.
+# For example, the article in 1948 (Korean Language) proved that DST
+# started at June 1 in that year.  For another example, the article in
+# 1988 said that DST started at 2:00 AM in that year.
+
 # Rule  NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER/S
-Rule    ROK     1960    only    -       May     15      0:00    1:00    D
-Rule    ROK     1960    only    -       Sep     13      0:00    0       S
-Rule    ROK     1987    1988    -       May     Sun>=8  0:00    1:00    D
-Rule    ROK     1987    1988    -       Oct     Sun>=8  0:00    0       S
+Rule    ROK     1948    only    -       Jun      1      0:00    1:00    D
+Rule    ROK     1948    only    -       Sep     13      0:00    0       S
+Rule    ROK     1949    only    -       Apr      3      0:00    1:00    D
+Rule    ROK     1949    1951    -       Sep     Sun>=8  0:00    0       S
+Rule    ROK     1950    only    -       Apr      1      0:00    1:00    D
+Rule    ROK     1951    only    -       May      6      0:00    1:00    D
+Rule    ROK     1955    only    -       May      5      0:00    1:00    D
+Rule    ROK     1955    only    -       Sep      9      0:00    0       S
+Rule    ROK     1956    only    -       May     20      0:00    1:00    D
+Rule    ROK     1956    only    -       Sep     30      0:00    0       S
+Rule    ROK     1957    1960    -       May     Sun>=1  0:00    1:00    D
+Rule    ROK     1957    1960    -       Sep     Sun>=18 0:00    0       S
+Rule    ROK     1987    1988    -       May     Sun>=8  2:00    1:00    D
+Rule    ROK     1987    1988    -       Oct     Sun>=8  3:00    0       S
 
-# From Paul Eggert (2014-07-01):
-# The following entries are from Shanks & Pottenger, except that I
-# guessed that time zone abbreviations through 1945 followed the same
+# From Paul Eggert (2014-10-30):
+# The Korean Wikipedia entry gives the following sources for UT offsets:
+#
+# 1908: Official Journal Article No. 3994 (Edict No. 5)
+# 1912: Governor-General of Korea Official Gazette Issue No. 367
+#       (Announcement No. 338)
+# 1954: Presidential Decree No. 876 (1954-03-17)
+# 1961: Law No. 676 (1961-08-07)
+# 1987: Law No. 3919 (1986-12-31)
+#
+# The Wikipedia entry also has confusing information about a change
+# to UT+9 in April 1910, but then what would be the point of the later change
+# to UT+9 on 1912-01-01?  Omit the 1910 change for now.
+#
+# I guessed that time zone abbreviations through 1945 followed the same
 # rules as discussed under Taiwan, with nominal switches from JST to KST
 # when the respective cities were taken over by the Allies after WWII.
+#
+# For Pyongyang we have no information; guess no changes since World War II.
 
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
-Zone    Asia/Seoul      8:27:52 -       LMT     1890
-                        8:30    -       KST     1904 Dec
-                        9:00    -       JCST    1928
-                        8:30    -       KST     1932
+Zone    Asia/Seoul      8:27:52 -       LMT     1908 Apr  1
+                        8:30    -       KST     1912 Jan  1
                         9:00    -       JCST    1937 Oct  1
                         9:00    -       JST     1945 Sep  8
                         9:00    -       KST     1954 Mar 21
-                        8:00    ROK     K%sT    1961 Aug 10
-                        8:30    -       KST     1968 Oct
+                        8:30    ROK     K%sT    1961 Aug 10
                         9:00    ROK     K%sT
-Zone    Asia/Pyongyang  8:23:00 -       LMT     1890
-                        8:30    -       KST     1904 Dec
-                        9:00    -       JCST    1928
-                        8:30    -       KST     1932
+Zone    Asia/Pyongyang  8:23:00 -       LMT     1908 Apr  1
+                        8:30    -       KST     1912 Jan  1
                         9:00    -       JCST    1937 Oct  1
                         9:00    -       JST     1945 Aug 24
-                        9:00    -       KST     1954 Mar 21
-                        8:00    -       KST     1961 Aug 10
                         9:00    -       KST
 
 ###############################################################################
 
 # Kuwait
-# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
-Zone    Asia/Kuwait     3:11:56 -       LMT     1950
-                        3:00    -       AST
+# See Asia/Riyadh.
 
 # 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
 Rule    Lebanon 1920    only    -       Mar     28      0:00    1:00    S
 Rule    Lebanon 1920    only    -       Oct     25      0:00    0       -
 Rule    Lebanon 1921    only    -       Apr     3       0:00    1:00    S

@@ -1930,17 +1947,12 @@
 Zone    Asia/Kathmandu  5:41:16 -       LMT     1920
                         5:30    -       IST     1986
                         5:45    -       NPT     # Nepal Time
 
 # Oman
+# See Asia/Dubai.
 
-# Milne says 3:54:24 was the meridian of the Muscat Tidal Observatory.
-
-# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
-Zone    Asia/Muscat     3:54:24 -       LMT     1920
-                        4:00    -       GST
-
 # Pakistan
 
 # From Rives McDow (2002-03-13):
 # I have been advised that Pakistan has decided to adopt dst on a
 # TRIAL basis for one year, starting 00:01 local time on April 7, 2002

@@ -2429,10 +2441,11 @@
 # Qatar
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
 Zone    Asia/Qatar      3:26:08 -       LMT     1920     # Al Dawhah / Doha
                         4:00    -       GST     1972 Jun
                         3:00    -       AST
+Link Asia/Qatar Asia/Bahrain
 
 # Saudi Arabia
 #
 # From Paul Eggert (2014-07-15):
 # Time in Saudi Arabia and other countries in the Arabian peninsula was not

@@ -2455,10 +2468,12 @@
 # the country.  Ignore this, as it's before our 1970 cutoff.
 #
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
 Zone    Asia/Riyadh     3:06:52 -       LMT     1947 Mar 14
                         3:00    -       AST
+Link Asia/Riyadh Asia/Aden      # Yemen
+Link Asia/Riyadh Asia/Kuwait
 
 # Singapore
 # taken from Mok Ly Yng (2003-10-30)
 # http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]

@@ -2726,10 +2741,12 @@
 # Thailand
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
 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.
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
 Zone    Asia/Ashgabat   3:53:32 -       LMT     1924 May  2 # or Ashkhabad

@@ -2741,10 +2758,11 @@
 
 # United Arab Emirates
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
 Zone    Asia/Dubai      3:41:12 -       LMT     1920
                         4:00    -       GST
+Link Asia/Dubai Asia/Muscat     # Oman
 
 # Uzbekistan
 # Byalokoz 1919 says Uzbekistan was 4:27:53.
 # Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
 Zone    Asia/Samarkand  4:27:53 -       LMT     1924 May  2

@@ -2763,31 +2781,68 @@
                         5:00 RussiaAsia UZ%sT   1992
                         5:00    -       UZT
 
 # 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 (2014-10-21) after a heads-up from Trần Ngọc Quân:
+# Trần Tiến Bình's authoritative book "Lịch Việt Nam: thế kỷ XX-XXI (1901-2100)"
+# (Nhà xuất bản Văn Hoá - Thông Tin, Hanoi, 2005), pp 49-50,
+# is quoted verbatim in:
+# http://www.thoigian.com.vn/?mPage=P80D01
+# is translated by Brian Inglis in:
+# http://mm.icann.org/pipermail/tz/2014-October/021654.html
+# and is the basis for the information below.
+#
+# 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.
+#
+# Trần cites the following sources; it's unclear which supplied the info above.
+#
+# Hoàng Xuân Hãn: "Lịch và lịch Việt Nam". Tập san Khoa học Xã hội,
+# No. 9, Paris, February 1982.
+#
+# Lê Thành Lân: "Lịch và niên biểu lịch sử hai mươi thế kỷ (0001-2010)",
+# NXB Thống kê, Hanoi, 2000.
+#
+# Lê Thành Lân: "Lịch hai thế kỷ (1802-2010) và các lịch vĩnh cửu",
+# NXB Thuận Hoá, Huế, 1995.
+
 # 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
-
-# Milne says 2:59:54 was the meridian of the saluting battery at Aden,
-# and that Yemen was at 1:55:56, the meridian of the Hagia Sophia.
-
-# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
-Zone    Asia/Aden       2:59:54 -       LMT     1950
-                        3:00    -       AST
+# See Asia/Riyadh.