From 41528a450e50b0fe223ebd47cbcaf8b6e3bbb65b Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Wed, 1 Jun 2022 19:02:41 -0700 Subject: [PATCH 3/3] Correct Iran transitions in 1977 and 1978 (Thanks to Roozbe Pournader.) * asia (Rule): Add a dummy rule to work around zic bug. 1978 transitions were 03-24 and 08-05 (the latter at 01:00), not 03-20 and 10-20 at 24:00. (Asia/Tehran): 1977 fall transition was directly from +0430 to +04. --- NEWS | 5 +++-- asia | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 56 insertions(+), 7 deletions(-) diff --git a/NEWS b/NEWS index de8aae9..ad28e92 100644 --- a/NEWS +++ b/NEWS @@ -17,8 +17,9 @@ Unreleased, experimental changes DST transitions were at 02:00 standard time, not at 00:00. (Thanks to Michael Deckers.) - Iran adopted standard time in 1935, not 1946. It observed DST - from 1977-03-21 23:00 to 1977-09-23 24:00, and its spring 1979 + Iran adopted standard time in 1935, not 1946. In 1977 it observed + DST from 03-21 23:00 to 09-23 24:00; its 1978 transitions were on + 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979 transition was on 05-27, not 03-21. (Thanks to Roozbeh Pournader.) diff --git a/asia b/asia index 2a939e0..149f11f 100644 --- a/asia +++ b/asia @@ -1426,6 +1426,51 @@ Zone Asia/Jayapura 9:22:48 - LMT 1932 Nov # For now use the same date for Tehran as for elsewhere in Iran. # This is most likely wrong, but we have no better info. +# From Roozbeh Pournader (2022-06-01): +# This is from Kayhan newspaper, one of the major Iranian newspapers, from +# March 20, 1978, page 2: +# +# "Pull the clocks 60 minutes forward +# As we informed before, from the fourth day of the month Farvardin of the +# new year [=1978-03-24], clocks will be pulled forward, and people's daily +# work and life program will start one hour earlier than the current program. +# On the 1st day of the month Farvardin of this year [=1977-03-21], they had +# pulled the clocks forward by one hour, but in the month of Mehr +# [=1977-09-23], the clocks were pulled back by 30 minutes. +# In this way, from the 4th day of the month Farvardin, clocks will be ahead +# of the previous years by one hour and a half. +# According to the new program, during the night of 4th of Farvardin, when +# the midnight, meaning 24 o'clock is announced, the hands of the clock must +# be pulled forward by one hour and thus consider midnight 1 o'clock in the +# forenoon." +# +# This implies that in September 1977, when the daylight savings time was +# done with, Iran didn't go back to +03:30, but immediately to +04:00. +# +# +# This is from the major Iranian newspaper Ettela'at, dated 1968-08-03, +# page 32. It looks like they decided to get the clocks back to +4:00 +# just in time for Ramadan that year: +# +# "Tomorrow Night, Pull the Clocks Back by One Hour +# At 1 o'clock in the forenoon of Saturday 14 Mordad [=1978-08-05], the +# clocks will be pulled one hour back and instead of 1 o'clock in the +# forenoon, Radio Iran will announce 24 o'clock. +# This decision was made in the Cabinet of Ministers meeting of 25 Tir +# [=1978-07-16], [...] +# At the beginning of the year 2537 [=March 1978: Iran was using a different +# year number for a few years then, based on the Coronation of Cyrus the +# Great], the country's official time was pulled forward by one hour and now +# the official time is one hour and a half ahead compared to last year, +# because in Farvardin of last year [=March 1977], the official time was +# pulled forward one hour and this continued until the second half of last +# year [=September 1977] until in the second half of last year the official +# time was pulled back half an hour and that half hour still remains." +# +# This matches the time of the true noon published in the newspapers, as they +# clearly go from +05:00 to +04:00 after that date (which happened during a +# long weekend in Iran). + # From Roozbeh Pournader (2022-05-31): # [Movahedi S. Cultural preconceptions of time: Can we use operational time # to meddle in God's Time? Comp Stud Soc Hist. 1985;27(3):385-400] @@ -1492,8 +1537,8 @@ Zone Asia/Jayapura 9:22:48 - LMT 1932 Nov # leap year calculation involved. There has never been any serious # plan to change that law.... # -# From Paul Eggert (2022-05-31): -# Go with Pournader for 1935 through 1977, for spring 1979, and for timestamps +# From Paul Eggert (2022-06-01): +# Go with Pournader for 1935 through spring 1979, and for timestamps # after August 1991; go with with Shanks & Pottenger for other timestamps. # # From Oscar van Vlijmen (2005-03-30), writing about future @@ -1535,10 +1580,13 @@ Zone Asia/Jayapura 9:22:48 - LMT 1932 Nov # (i.e 2023-March-21) and forthcoming years. # # Rule NAME FROM TO - IN ON AT SAVE LETTER/S +# Work around a bug in zic 2022a and earlier. +Rule Iran 1910 only - Jan 1 00:00 0 - +# Rule Iran 1977 only - Mar 21 23:00 1:00 - Rule Iran 1977 only - Sep 23 24:00 0 - -Rule Iran 1978 only - Mar 20 24:00 1:00 - -Rule Iran 1978 only - Oct 20 24:00 0 - +Rule Iran 1978 only - Mar 24 24:00 1:00 - +Rule Iran 1978 only - Aug 5 01:00 0 - Rule Iran 1979 only - May 26 24:00 1:00 - Rule Iran 1979 only - Sep 18 24:00 0 - Rule Iran 1980 only - Mar 20 24:00 1:00 - @@ -1578,7 +1626,7 @@ Rule Iran 2021 2022 - Sep 21 24:00 0 - # Zone NAME STDOFF RULES FORMAT [UNTIL] Zone Asia/Tehran 3:25:44 - LMT 1916 3:25:44 - TMT 1935 Jun 13 # Tehran Mean Time - 3:30 Iran +0330/+0430 1977 Nov + 3:30 Iran +0330/+0430 1977 Sep 23 24:00 4:00 Iran +04/+05 1979 3:30 Iran +0330/+0430 -- 2.36.1