>From eea490a7f87a6c49ab9a292bb6f144177171a739 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sat, 17 Nov 2018 11:17:23 -0800 Subject: [PROPOSED] Hong Kong fixes for 1904 through 1952 * NEWS: Mention this. * asia (HK): Eliminate 1941 rules; now done in Zone to avoid glitch in fall transition. Coalesce 1952 and 1953 fallback rule. (Asia/Hong_Kong): Use time ball drop for first transition. Brief period of +08:30 standard time in late 1941. Adjust 1941 transitions. --- NEWS | 8 +++++ asia | 95 ++++++++++++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 85 insertions(+), 18 deletions(-) diff --git a/NEWS b/NEWS index e3d62a6..83081a7 100644 --- a/NEWS +++ b/NEWS @@ -21,6 +21,14 @@ Unreleased, experimental changes It did not change clocks that day and is now on -08 indefinitely, reverting to its form before fall 2015. (Thanks to Ryan Stanley.) + Change to past time stamps + + Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on + 10-01 changed standard time to +08:30 (not +08). Its transition + back to +08 after WWII was on 1945-09-15, not the previous day. + (Thanks to Phake Nick.) Its 1952 fallback was on 11-02 (not 10-25). + Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT). + Changes to past tm_isdst flags For the recent Morocco change, the tm_isdst flag should be 1 from diff --git a/asia b/asia index ff7f73f..12c92e5 100644 --- a/asia +++ b/asia @@ -586,12 +586,59 @@ Zone Asia/Urumqi 5:50:20 - LMT 1928 # obtained from # http://www.hko.gov.hk/gts/time/Summertime.htm -# From Arthur David Olson (2009-10-28): +# From Phake Nick (2018-10-27): +# According to Singaporean newspaper +# http://eresources.nlb.gov.sg/newspapers/Digitised/Article/singfreepresswk19041102-1.2.37 +# the day that Hong Kong start using GMT+8 should be Oct 30, 1904. +# +# From Paul Eggert (2018-11-17): +# Assume the 1904 switch occurred when the time ball was dropped. +# "From 1904 October 30 the time-ball at Hong Kong has been dropped by order +# of the Governor of the Colony at 17h 0h 0s G.M.T., which is 23m 18s.14 in +# advance of 1h 0m 0s of Hong Kong mean time." +# H.P.H. Universal Time, Longitudes, and Geodesy. Mon Not R Astron Soc. +# 1905-02-10;65(4):405-6. https://doi.org/10.1093/mnras/65.4.382 + +# From Phake Nick (2018-10-26): +# I went to check microfilm records stored at Hong Kong Public Library.... +# on September 30 1941, according to Ta Kung Pao (Hong Kong edition), it was +# stated that fallback would occur on the next day (the 1st)'s "03:00 am (Hong +# Kong Time 04:00 am)" and the clock will fall back for a half hour. (03:00 +# probably refer to the time commonly used in mainland China at the time given +# the paper's background) ... the sunrise/sunset time given by South China +# Morning Post for October 1st was indeed moved by half an hour compares to +# before. After that, in December, the battle to capture Hong Kong started and +# the library doesn't seems to have any record stored about press during that +# period of time. Some media resumed publication soon after that within the +# same month, but there were not much information about time there. Later they +# started including a radio program guide when they restored radio service, +# explicitly mentioning it use Tokyo standard time, and later added a note +# saying it's half an hour ahead of the old Hong Kong standard time, and it +# also seems to indicate that Hong Kong was not using GMT+8 when it was +# captured by Japan. +# +# Image of related sections on newspaper: +# * 1941-09-30, Ta Kung Pao (Hing Kong), "Winter Time start tomorrow". +# https://i.imgur.com/6waY51Z.jpg (Chinese) +# * 1941-09-29, South China Morning Post, Information on sunrise/sunset +# time and other things for September 30 and October 1. +# https://i.imgur.com/kCiUR78.jpg +# * 1942-02-05. The Hong Kong News, Radio Program Guide. +# https://i.imgur.com/eVvDMzS.jpg +# * 1941-06-14. Hong Kong Daily Press, Daylight Saving from 3am Tomorrow. +# https://i.imgur.com/05KkvtC.png +# * 1941-09-30, Hong Kong Daily Press, Winter Time Warning. +# https://i.imgur.com/dge4kFJ.png +# Also, the Liberation day of Hong Kong after WWII which British rule +# over the territory resumed was August 30, 1945, which I think should +# be the termination date for the use of JST in the territory.... + +# From Paul Eggert (2018-11-17): # Here are the dates given at -# http://www.hko.gov.hk/gts/time/Summertime.htm -# as of 2009-10-28: +# https://www.hko.gov.hk/gts/time/Summertime.htm +# as of 2014-06-19: # Year Period -# 1941 1 Apr to 30 Sep +# 1941 15 Jun to 30 Sep # 1942 Whole year # 1943 Whole year # 1944 Whole year @@ -602,7 +649,7 @@ Zone Asia/Urumqi 5:50:20 - LMT 1928 # 1949 3 Apr to 30 Oct # 1950 2 Apr to 29 Oct # 1951 1 Apr to 28 Oct -# 1952 6 Apr to 25 Oct +# 1952 6 Apr to 2 Nov # 1953 5 Apr to 1 Nov # 1954 21 Mar to 31 Oct # 1955 20 Mar to 6 Nov @@ -631,25 +678,25 @@ Zone Asia/Urumqi 5:50:20 - LMT 1928 # 1978 Nil # 1979 13 May to 21 Oct # 1980 to Now Nil -# The page does not give start or end times of day. -# The page does not give a start date for 1942. -# The page does not givw an end date for 1945. -# The Japanese occupation of Hong Kong began on 1941-12-25. -# The Japanese surrender of Hong Kong was signed 1945-09-15. -# For lack of anything better, use start of those days as the transition times. +# The page does not give times of day for transitions, +# or dates for the 1942 and 1945 transitions. +# The Japanese occupation of Hong Kong began 1941-12-25. +# The Japanese surrender of Hong Kong was signed 1945-09-16; see: +# Heaver S. The days after the Pacific war ended: unsettling times +# in Hong Kong. Post Magazine. 2016-06-13. +# https://www.scmp.com/magazines/post-magazine/article/1852990/days-after-pacific-war-ended-unsettling-times-hong-kong +# For lack of anything better, use start of those days as the +# transition times. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule HK 1941 only - Apr 1 3:30 1:00 S -Rule HK 1941 only - Sep 30 3:30 0 - Rule HK 1946 only - Apr 20 3:30 1:00 S Rule HK 1946 only - Dec 1 3:30 0 - Rule HK 1947 only - Apr 13 3:30 1:00 S Rule HK 1947 only - Dec 30 3:30 0 - Rule HK 1948 only - May 2 3:30 1:00 S Rule HK 1948 1951 - Oct lastSun 3:30 0 - -Rule HK 1952 only - Oct 25 3:30 0 - +Rule HK 1952 1953 - Nov Sun>=1 3:30 0 - Rule HK 1949 1953 - Apr Sun>=1 3:30 1:00 S -Rule HK 1953 only - Nov 1 3:30 0 - Rule HK 1954 1964 - Mar Sun>=18 3:30 1:00 S Rule HK 1954 only - Oct 31 3:30 0 - Rule HK 1955 1964 - Nov Sun>=1 3:30 0 - @@ -659,9 +706,11 @@ Rule HK 1973 only - Dec 30 3:30 1:00 S Rule HK 1979 only - May Sun>=8 3:30 1:00 S Rule HK 1979 only - Oct Sun>=16 3:30 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Hong_Kong 7:36:42 - LMT 1904 Oct 30 - 8:00 HK HK%sT 1941 Dec 25 - 9:00 - JST 1945 Sep 15 +Zone Asia/Hong_Kong 7:36:42 - LMT 1904 Oct 29 17:00u + 8:00 - HKT 1941 Jun 15 3:30 + 8:00 1:00 HKST 1941 Oct 1 4:00 + 8:30 - HKT 1941 Dec 25 + 9:00 - JST 1945 Sep 16 8:00 HK HK%sT ############################################################################### @@ -1057,6 +1106,16 @@ Zone Asia/Dili 8:22:20 - LMT 1912 Jan 1 # India +# A British astronomer disapproved when India Standard Time was proposed: +# "A new time system has been proposed for India, Further India, and Burmah. +# The scheme suggested is that the times of the meridians 5�� and 6�� hours +# east of Greenwich should be adopted in these territories. No reason is +# given why hourly meridians five hours and six hours east should not be +# chosen; a plan which would bring the time of India into harmony with +# that of almost the whole of the civilised world." +# H.P.H. Universal Time, Longitudes, and Geodesy. Mon Not R Astron Soc. +# 1905-02-10;65(4):405-6. https://doi.org/10.1093/mnras/65.4.382 + # From Ian P. Beacock, in "A brief history of (modern) time", The Atlantic # https://www.theatlantic.com/technology/archive/2015/12/the-creation-of-modern-time/421419/ # (2015-12-22): -- 2.17.1