[tz] [PATCH] * asia (Asia/Seoul) correct DST.
Paul Eggert
eggert at cs.ucla.edu
Fri Oct 31 06:53:09 UTC 2014
Thank you. I noticed a minor error in the proposed rules, namely "Sep Sun>=20"
should be "Sun Sep>=18" for 1960-09-18 to work.
More important, the Wikipedia data for times before 1961 disagree with the tz
database, which suggests that more corrections are needed. While we're in the
neighborhood, it's completely implausible that Pyongyang faithfully mimicked
Seoul time during and after the Korean war (which is what Shanks says), so let's
remove that obviously-bogus guess. Attached is a proposed patch that tries to
capture all this.
Unfortunately I am puzzled by the Wikipedia text "1910년 4월: 동경 135° UTC+9:로
변경." This cites "여적 표준시 변경, 경향신문, 2000-08-14", a source that I
cannot easily read. If Korea switched to UT+9 in April 1910, then why is there
a later entry for 1912 that says "동경 135° UTC+9로 변경. 조선총독부 관보 제367
호(고시 제338호)"? That is, if Korea switched to UT+9 in 1910 why did they also
switch to UT+9 in 1912? If you could clarify this point I would appreciate it.
Thank you again.
-------------- next part --------------
From 929c14a3d8ce505a9b8fb7099bee3a03ccf7e8e4 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
Date: Thu, 30 Oct 2014 23:27:26 -0700
Subject: [PROPOSED PATCH] Correct many pre-1989 entries for Korea.
(Thanks to Sanghyuk Jung.)
* asia (ROK): Add entries for 1948-1959 and correct entries
for 1987-1988.
(Asia/Seoul): Correct entries through 1962.
(Asia/Pyongyang): Guess no change since World War II.
* NEWS: Document this.
---
NEWS | 11 ++++++++++
asia | 77 ++++++++++++++++++++++++++++++++++++++++++++++----------------------
2 files changed, 63 insertions(+), 25 deletions(-)
diff --git a/NEWS b/NEWS
index 4e119ec..2485c93 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,16 @@
News for the tz database
+Unreleased, experimental changes
+
+ Changes affecting past time stamps
+
+ Many pre-1989 time stamps have been corrected for Asia/Seoul and
+ Asia/Pyongyang, based on sources for the Korean-language Wikipedia
+ entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
+ longer guess that Pyongyang mimicked Seoul time after World War II,
+ as this is politically implausible.
+
+
Release 2014i - 2014-10-21 22:04:57 -0700
Changes affecting future time stamps
diff --git a/asia b/asia
index 37b2c88..217e8ee 100644
--- a/asia
+++ b/asia
@@ -1663,44 +1663,71 @@ Zone Asia/Bishkek 4:58:24 - LMT 1924 May 2
# 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 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.
-# From Shanks & Pottenger:
# 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
-
-# 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
+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 (2014-10-30):
+# 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 ROK K%sT 1961 Aug 10
8:30 - KST 1968 Oct
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
###############################################################################
--
1.9.1
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