From b266263699ab1b02d7d4b7307e5303181bea00c1 Mon Sep 17 00:00:00 2001
From: Paul Eggert
Date: Thu, 7 Dec 2017 22:29:53 -0800
Subject: [PROPOSED] Ireland observes standard time in summer, not winter
(Discrepancy noted by Derick Rethans.)
* NEWS: Document this.
* europe (Eire): New ruleset.
(Europe/Dublin): Use it.
* theory.html (Time zone abbreviations): Fix IST.
---
NEWS | 11 +++++++++++
europe | 38 ++++++++++++++++++++++++++++++++------
theory.html | 3 ++-
3 files changed, 45 insertions(+), 7 deletions(-)
diff --git a/NEWS b/NEWS
index 239dd33..51786c6 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,17 @@ Unreleased, experimental changes
BST instead of BOST, to be more consistent with the convention
used for Latvian Summer Time (1918-9) and for British Summer Time.
+ Changes to tm_isdst
+
+ Change Europe/Dublin so that it observes Irish Standard Time (UT
+ +01) in summer and GMT (as negative daylight-saving) in winter,
+ instead of observing standard time (GMT) in winter and Irish
+ Summer Time (UT +01) in summer. This change does not affect UT
+ offsets or abbreviations; it affects only whether timestamps are
+ considered to be standard time or daylight-saving time, as
+ expressed in the tm_isdst flag of C's struct tm type.
+ (Discrepancy noted by Derick Rethans.)
+
Changes to build procedure
The default installation procedure no longer creates the
diff --git a/europe b/europe
index 4409be3..0fd3cc2 100644
--- a/europe
+++ b/europe
@@ -68,6 +68,7 @@
# 0:00 WET WEST WEMT Western Europe
# 0:19:32.13 AMT* NST* Amsterdam, Netherlands Summer (1835-1937)
# 1:00 BST British Standard (1968-1971)
+# 1:00 IST GMT Irish Standard (1968-) with winter DST
# 1:00 CET CEST CEMT Central Europe
# 1:00:14 SET Swedish (1879-1899)
# 1:36:34 RMT* LST* Riga, Latvian Summer (1880-1926)*
@@ -362,12 +363,28 @@
# regulations. I spoke this morning with the Secretary of the Department of
# Justice (tel +353 1 678 9711) who confirmed to me that the correct name is
# "Irish Summer Time", abbreviated to "IST".
+#
+# From Paul Eggert (2017-12-07):
+# The 1996 anonymous contributor's goal was to determine the correct
+# abbreviation for summer time in Dublin and so the contributor
+# focused on the "IST", not on the "Irish Summer Time". Though the
+# "IST" was correct, the "Irish Summer Time" appears to have been an
+# error, as Ireland's Standard Time (Amendment) Act, 1971 states that
+# standard time in Ireland remains at UT +01 and is observed in
+# summer, and that Greenwich mean time is observd in winter. (Thanks
+# to Derick Rethans for pointing out the error.) That is, when
+# Ireland amended the 1968 act that established UT +01 as Irish
+# Standard Time, it left standard time unchanged and established GMT
+# as a negative daylight saving time in winter. So, in this database
+# IST stands for Irish Summer Time for timestamps before 1968, and for
+# Irish Standard Time after that. See:
+# http://www.irishstatutebook.ie/eli/1971/act/17/enacted/en/print
# Michael Deckers (2017-06-01) gave the following URLs for Ireland's
# Summer Time Act, 1925 and Summer Time Orders, 1926 and 1947:
-# http://www.irishstatutebook.ie/eli/1925/act/8/enacted/en/print.html
-# http://www.irishstatutebook.ie/eli/1926/sro/919/made/en/print.html
-# http://www.irishstatutebook.ie/eli/1947/sro/71/made/en/print.html
+# http://www.irishstatutebook.ie/eli/1925/act/8/enacted/en/print
+# http://www.irishstatutebook.ie/eli/1926/sro/919/made/en/print
+# http://www.irishstatutebook.ie/eli/1947/sro/71/made/en/print
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# Summer Time Act, 1916
@@ -491,6 +508,17 @@ Link Europe/London Europe/Jersey
Link Europe/London Europe/Guernsey
Link Europe/London Europe/Isle_of_Man
+# The following is like GB-Eire and EU, except with standard time in
+# summer and negative daylight saving time in winter.
+# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
+Rule Eire 1971 only - Oct 31 2:00u -1:00 GMT
+Rule Eire 1972 1980 - Mar Sun>=16 2:00u 0 IST
+Rule Eire 1972 1980 - Oct Sun>=23 2:00u -1:00 GMT
+Rule Eire 1981 max - Mar lastSun 1:00u 0 IST
+Rule Eire 1981 1989 - Oct Sun>=23 1:00u -1:00 GMT
+Rule Eire 1990 1995 - Oct Sun>=22 1:00u -1:00 GMT
+Rule Eire 1996 max - Oct lastSun 1:00u -1:00 GMT
+
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2
-0:25:21 - DMT 1916 May 21 2:00s
@@ -502,9 +530,7 @@ Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2
0:00 1:00 IST 1947 Nov 2 2:00s
0:00 - GMT 1948 Apr 18 2:00s
0:00 GB-Eire GMT/IST 1968 Oct 27
- 1:00 - IST 1971 Oct 31 2:00u
- 0:00 GB-Eire GMT/IST 1996
- 0:00 EU GMT/IST
+ 1:00 Eire IST/GMT
###############################################################################
diff --git a/theory.html b/theory.html
index 8ea5771..dbc7660 100644
--- a/theory.html
+++ b/theory.html
@@ -330,6 +330,7 @@ GST Guam,
HST/HDT Hawaii,
HKT/HKST Hong Kong,
IST India,
+IST/GMT Irish,
IST/IDT/IDDT Israel,
JST/JDT Japan,
KST/KDT Korea,
@@ -387,7 +388,7 @@ TMT Tallinn, Tehran;
WMT Warsaw.
A few abbreviations also follow the pattern that
-GMT/BST/IST/BDST established for time in the UK. They are:
+GMT/BST established for time in the UK. They are:
CMT/BST for Calamarca Mean Time and Bolivian Summer Time
1890–1932, DMT/IST for Dublin/Dunsink Mean Time and Irish Summer Time
--
2.7.4