From: Paul Eggert <eggert@Penguin.CS.UCLA.EDU> * NEWS: Document this. * asia (Asia/Yangon): Add 7 s to times from 1880 to 1920. (Asia/Kolkata): Switch from HMT to MMT in 1870, and from MMT to IST in 1906. --- NEWS | 11 +++++++++++ asia | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 64 insertions(+), 6 deletions(-) diff --git a/NEWS b/NEWS index f986cf6..ad099f4 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,16 @@ News for the tz database +Unreleased, experimental changes + + Changes to past time stamps + + Use railway time for Asia/Kolkata before 1941, by switching to + Madras local time (UT +052110) in 1870, then to IST (UT +0530) in + 1906. Also, treat 1941-2's +0630 as DST, like 1942-5. + + Add 7 s to the UT offset in Asia/Yangon before 1920. + + Release 2017b - 2017-03-17 07:30:38 -0700 Briefly: Haiti has resumed DST. diff --git a/asia b/asia index 35774c6..f027071 100644 --- a/asia +++ b/asia @@ -258,9 +258,15 @@ Zone Asia/Brunei 7:39:40 - LMT 1926 Mar # Bandar Seri Begawan # Milne says 6:24:40 was the meridian of the time ball observatory at Rangoon. +# From Paul Eggert (2017-04-20): +# Page 27 of Reed & Low (cited for Asia/Kolkata) says "Rangoon local time is +# used upon the railways and telegraphs of Burma, and is 6h. 24m. 47s. ahead +# of Greenwich." This refers to the period before Burma's transition to +0630, +# a transition for which Shanks is the only source. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Yangon 6:24:40 - LMT 1880 # or Rangoon - 6:24:40 - RMT 1920 # Rangoon Mean Time? +Zone Asia/Yangon 6:24:47 - LMT 1880 # or Rangoon + 6:24:47 - RMT 1920 # Rangoon local time 6:30 - +0630 1942 May 9:00 - +09 1945 May 3 6:30 - +0630 @@ -887,14 +893,55 @@ Zone Asia/Dili 8:22:20 - LMT 1912 Jan 1 # local time in favor of Indian Standard Time.... Journalists called this # dispute the "Battle of the Clocks." It lasted nearly half a century. +# From Paul Eggert (2017-04-20): +# Good luck trying to nail down old timekeeping records in India. +# "... in the nineteenth century ... Madras Observatory took its magnetic +# measurements in Göttingen time, its meterological measurements on Madras +# (local) time, dropped its time ball on Greenwich (ocean navigator's) time, +# and distributed civil (local time)." -- Bartky IR. Selling the time: +# 19th-century timekeeping in america. Stanford U Press (2000), 247 note 19. +# "A more potent cause of resistance to the general adoption of the present +# standard time lies in the fact that it is Madras time. The citizen of +# Bombay, proud of being 'primus in Indis' and of Calcutta, equally proud of +# his city being the Capital of India, and - for a part of the year - the Seat +# of the Supreme Government, alike look down on Madras, and refuse to change +# the time they are using, for that of what they regard as a benighted +# Presidency; while Madras, having for long given the standard time to the +# rest of India, would resist the adoption of any other Indian standard in its +# place." -- Oldham RD. On Time in India: a suggestion for its improvement. +# Proceedings of the Asiatic Society of Bengal (April 1899), 49-55. +# +# "In 1870 ... Madras time - 'now used by the telegraph and regulated from the +# only government observatory' - was suggested as a standard railway time, +# first to be dopted on the Great Indian Peninsular Railway (GIPR).... +# Calcutta, Bombay, and Karachi, were to be allowed to continue with their +# local time for civil purposes." - Prasad R. Tracks of Change: Railways and +# Everyday Life in Colonial India. Cambridge University Press (2016), 145. +# +# Reed S, Low F. The Indian Year Book 1936-37. Bennett, Coleman, pp 27-8. +# https://archive.org/details/in.ernet.dli.2015.282212 +# This lists +052110 as Madras local time used in railways, and says that on +# 1906-01-01 railways and telegraphs in India switched to +0530. Some +# municipalities retained their former time, and the time in Calcutta +# continued to depend on whether you were at the railway station or at +# government offices. Government time was at +055320 (according to Shanks) or +# at +0554 (according to the Indian Year Book). Railway time is more +# appropriate for our purposes, as it was better documented, it is what we do +# elsewhere (e.g., Europe/London before 1880), and after 1906 it was +# consistent in the region now identified by Asia/Kolkata. So, use railway +# time for 1870-1941. Shanks is our only (and dubious) source for the +# 1941-1945 data. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Kolkata 5:53:28 - LMT 1880 # Kolkata - 5:53:20 - HMT 1941 Oct # Howrah Mean Time? - 6:30 - +0630 1942 May 15 +Zone Asia/Kolkata 5:53:28 - LMT 1854 Jun 28 # Kolkata + 5:53:20 - HMT 1870 # Howrah Mean Time? + 5:21:10 - MMT 1906 Jan 1 # Madras local time + 5:30 - IST 1941 Oct + 5:30 1:00 +0630 1942 May 15 5:30 - IST 1942 Sep 5:30 1:00 +0630 1945 Oct 15 5:30 - IST -# The following are like Asia/Kolkata: +# Since 1970 the following are like Asia/Kolkata: # Andaman Is # Lakshadweep (Laccadive, Minicoy and Amindivi Is) # Nicobar Is -- 2.9.3