>From c6b83759b2a4e4436c6009a441f9c8c3438a8604 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sat, 17 Nov 2018 17:53:07 -0800 Subject: [PROPOSED] Revert recent change to 1904 HK transition * NEWS, asia (Asia/Hong_Kong): Go back to omitting time of day for 1904-10-30 transition. (Thanks to Michael Deckers.) --- NEWS | 1 - asia | 20 +++++++++++--------- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/NEWS b/NEWS index 83081a7..0bea722 100644 --- a/NEWS +++ b/NEWS @@ -27,7 +27,6 @@ Unreleased, experimental changes 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 diff --git a/asia b/asia index 1568f2d..54df1a2 100644 --- a/asia +++ b/asia @@ -592,12 +592,14 @@ Zone Asia/Urumqi 5:50:20 - LMT 1928 # 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 +# Hong Kong had a time ball nearthe Marine Police Station, Tsim Sha Tsui. +# "The ball was raised manually each day and dropped at exactly 1pm +# (except on Sundays and Government holidays)." +# Dyson AD. From Time Ball to Atomic Clock. Hong Kong Government. 1983. +# +# As 1904-10-30 was a Sunday, most likely the time change did not +# propagate to most of Hong Kong until the afternoon of the next day. +# For now, just record the date, not any time of day. # From Phake Nick (2018-10-26): # I went to check microfilm records stored at Hong Kong Public Library.... @@ -706,7 +708,7 @@ 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 29 17:00u +Zone Asia/Hong_Kong 7:36:42 - LMT 1904 Oct 30 8:00 - HKT 1941 Jun 15 3:30 8:00 1:00 HKST 1941 Oct 1 4:00 8:30 - HKT 1941 Dec 25 @@ -1106,14 +1108,14 @@ Zone Asia/Dili 8:22:20 - LMT 1912 Jan 1 # India -# A British astronomer disapproved when India Standard Time was proposed: +# British astronomer Henry Park Hollis disliked India Standard Time's offset: # "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. +# Hollis HP. 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 -- 2.17.1