[tz] [PATCH 0/2] Follow Australian common usage and update CST/CST to CST/CDT and EST/EST to EST/EDT etc [SEC=UNCLASSIFIED]

Paul Eggert eggert at cs.ucla.edu
Mon Jun 30 07:46:55 UTC 2014


On 2013-04-12 Russ Allbery wrote:
> I'm increasingly of the opinion that the tz database should just use the
> most unambiguous abbreviations (AEST/AEDT) even if there isn't a clear
> consensus in general usage.

I am tempted to agree, particularly since (prompted by Rich Tibbett's 
proposed patch on github) I finally got around to surveying general 
usage and it appears that there is a working (though by no means 
universal) consensus in Australia to use abbreviations like "AEST" and 
"AEDT", and furthmore, we appear to have been mistaken in our 
assumptions about abbreviation usage in the past.  Details are in the 
attached proposed patch, which I've pushed into the experimental tz 
version on github.  I couldn't resist adding a quote about the 
daylight-saving preferences of "chuckleheaded Queenslanders and 
straw-chewing yokels from the West".
-------------- next part --------------
From 62df86e10cb45ed931850f7298fa063ffea07544 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
Date: Mon, 30 Jun 2014 00:35:15 -0700
Subject: [PATCH] Use AEST/AEDT etc. instead of EST etc. for Australian
 abbreviations.

* NEWS, australasia (Aus, Australia/Darwin, AW, Australia/Perth)
(Australia/Eucla, AQ, Holiday, Australia/Brisbane, Australia/Lindeman)
(AS, Australia/Adelaide, AT, Australia/Hobart, Australia/Currie, AV)
(Australia/Melbourne, AN, Australia/Sydney, Australia/Broken_Hill)
(LH, Australia/Lord_Howe, Antarctica/Macquarie):
Prefix Australian time zone abbreviations with "A", and switch
from "ST" to "DT" to denote daylight saving time.  (Thanks to Ian
Abbott, Russ Allbery, Timothy Arceri, Alan Barrett, Stuart Bishop,
Shaun Bouckaert, Stephen Colebourne, Tobias Conradi, Mark Davis,
Robert Elz, Clive D.W. Feather, Dennis Ferguson, Edwin Groothuis,
Guy Harris, John Hawkinson, John Haxby, Brian Inglis, Paul Koning,
Kevin Lyda, Curtis Manwaring, Alan Mintz, Arthur David Olson, Matt
Paine, David Patte, Tim Parenti, random832, Derick Rethans, SM,
Peter Stagg, Rich Tibbett, Bennett Todd, and Garrett Wollman for
their contributions to this topic.)
---
 NEWS        |  10 ++
 australasia | 510 +++++++++++++++++++++++++++++++-----------------------------
 2 files changed, 275 insertions(+), 245 deletions(-)

diff --git a/NEWS b/NEWS
index 162a113..05a7063 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,16 @@ News for the tz database
 
 Unreleased, experimental changes
 
+  Changes affecting time zone abbreviations
+
+    Australian eastern time zone abbreviations are now AEST/AEDT not EST,
+    and similarly for the other Australian zones.  That is, for eastern
+    standard and daylight saving time the abbreviations are AEST and AEDT
+    instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
+    and AWST/AWDT are now used instead of the former CST, CWST, and WST.
+    This change does not affect UTC offsets, only time zone abbreviations.
+    (Thanks to Rich Tibbett and many others.)
+
   Changes affecting past time stamps
 
     Finland's 1942 fall-back transition was October 4 at 01:00, not
diff --git a/australasia b/australasia
index 1cb34a3..69f61f1 100644
--- a/australasia
+++ b/australasia
@@ -12,13 +12,13 @@
 # Please see the notes below for the controversy about "EST" versus "AEST" etc.
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Aus	1917	only	-	Jan	 1	0:01	1:00	-
-Rule	Aus	1917	only	-	Mar	25	2:00	0	-
-Rule	Aus	1942	only	-	Jan	 1	2:00	1:00	-
-Rule	Aus	1942	only	-	Mar	29	2:00	0	-
-Rule	Aus	1942	only	-	Sep	27	2:00	1:00	-
-Rule	Aus	1943	1944	-	Mar	lastSun	2:00	0	-
-Rule	Aus	1943	only	-	Oct	 3	2:00	1:00	-
+Rule	Aus	1917	only	-	Jan	 1	0:01	1:00	D
+Rule	Aus	1917	only	-	Mar	25	2:00	0	S
+Rule	Aus	1942	only	-	Jan	 1	2:00	1:00	D
+Rule	Aus	1942	only	-	Mar	29	2:00	0	S
+Rule	Aus	1942	only	-	Sep	27	2:00	1:00	D
+Rule	Aus	1943	1944	-	Mar	lastSun	2:00	0	S
+Rule	Aus	1943	only	-	Oct	 3	2:00	1:00	D
 # Go with Whitman and the Australian National Standards Commission, which
 # says W Australia didn't use DST in 1943/1944.  Ignore Whitman's claim that
 # 1944/1945 was just like 1943/1944.
@@ -26,26 +26,26 @@ Rule	Aus	1943	only	-	Oct	 3	2:00	1:00	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 # Northern Territory
 Zone Australia/Darwin	 8:43:20 -	LMT	1895 Feb
-			 9:00	-	CST	1899 May
-			 9:30	Aus	CST
+			 9:00	-	ACST	1899 May
+			 9:30	Aus	AC%sT
 # Western Australia
 #
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	AW	1974	only	-	Oct	lastSun	2:00s	1:00	-
-Rule	AW	1975	only	-	Mar	Sun>=1	2:00s	0	-
-Rule	AW	1983	only	-	Oct	lastSun	2:00s	1:00	-
-Rule	AW	1984	only	-	Mar	Sun>=1	2:00s	0	-
-Rule	AW	1991	only	-	Nov	17	2:00s	1:00	-
-Rule	AW	1992	only	-	Mar	Sun>=1	2:00s	0	-
-Rule	AW	2006	only	-	Dec	 3	2:00s	1:00	-
-Rule	AW	2007	2009	-	Mar	lastSun	2:00s	0	-
-Rule	AW	2007	2008	-	Oct	lastSun	2:00s	1:00	-
+Rule	AW	1974	only	-	Oct	lastSun	2:00s	1:00	D
+Rule	AW	1975	only	-	Mar	Sun>=1	2:00s	0	S
+Rule	AW	1983	only	-	Oct	lastSun	2:00s	1:00	D
+Rule	AW	1984	only	-	Mar	Sun>=1	2:00s	0	S
+Rule	AW	1991	only	-	Nov	17	2:00s	1:00	D
+Rule	AW	1992	only	-	Mar	Sun>=1	2:00s	0	S
+Rule	AW	2006	only	-	Dec	 3	2:00s	1:00	D
+Rule	AW	2007	2009	-	Mar	lastSun	2:00s	0	S
+Rule	AW	2007	2008	-	Oct	lastSun	2:00s	1:00	D
 Zone Australia/Perth	 7:43:24 -	LMT	1895 Dec
-			 8:00	Aus	WST	1943 Jul
-			 8:00	AW	WST
+			 8:00	Aus	AW%sT	1943 Jul
+			 8:00	AW	AW%sT
 Zone Australia/Eucla	 8:35:28 -	LMT	1895 Dec
-			 8:45	Aus	CWST	1943 Jul
-			 8:45	AW	CWST
+			 8:45	Aus	ACW%sT	1943 Jul
+			 8:45	AW	ACW%sT
 
 # Queensland
 #
@@ -61,42 +61,42 @@ Zone Australia/Eucla	 8:35:28 -	LMT	1895 Dec
 # so use Lindeman.
 #
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	AQ	1971	only	-	Oct	lastSun	2:00s	1:00	-
-Rule	AQ	1972	only	-	Feb	lastSun	2:00s	0	-
-Rule	AQ	1989	1991	-	Oct	lastSun	2:00s	1:00	-
-Rule	AQ	1990	1992	-	Mar	Sun>=1	2:00s	0	-
-Rule	Holiday	1992	1993	-	Oct	lastSun	2:00s	1:00	-
-Rule	Holiday	1993	1994	-	Mar	Sun>=1	2:00s	0	-
+Rule	AQ	1971	only	-	Oct	lastSun	2:00s	1:00	D
+Rule	AQ	1972	only	-	Feb	lastSun	2:00s	0	S
+Rule	AQ	1989	1991	-	Oct	lastSun	2:00s	1:00	D
+Rule	AQ	1990	1992	-	Mar	Sun>=1	2:00s	0	S
+Rule	Holiday	1992	1993	-	Oct	lastSun	2:00s	1:00	D
+Rule	Holiday	1993	1994	-	Mar	Sun>=1	2:00s	0	S
 Zone Australia/Brisbane	10:12:08 -	LMT	1895
-			10:00	Aus	EST	1971
-			10:00	AQ	EST
+			10:00	Aus	AE%sT	1971
+			10:00	AQ	AE%sT
 Zone Australia/Lindeman  9:55:56 -	LMT	1895
-			10:00	Aus	EST	1971
-			10:00	AQ	EST	1992 Jul
-			10:00	Holiday	EST
+			10:00	Aus	AE%sT	1971
+			10:00	AQ	AE%sT	1992 Jul
+			10:00	Holiday	AE%sT
 
 # South Australia
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	AS	1971	1985	-	Oct	lastSun	2:00s	1:00	-
-Rule	AS	1986	only	-	Oct	19	2:00s	1:00	-
-Rule	AS	1987	2007	-	Oct	lastSun	2:00s	1:00	-
-Rule	AS	1972	only	-	Feb	27	2:00s	0	-
-Rule	AS	1973	1985	-	Mar	Sun>=1	2:00s	0	-
-Rule	AS	1986	1990	-	Mar	Sun>=15	2:00s	0	-
-Rule	AS	1991	only	-	Mar	3	2:00s	0	-
-Rule	AS	1992	only	-	Mar	22	2:00s	0	-
-Rule	AS	1993	only	-	Mar	7	2:00s	0	-
-Rule	AS	1994	only	-	Mar	20	2:00s	0	-
-Rule	AS	1995	2005	-	Mar	lastSun	2:00s	0	-
-Rule	AS	2006	only	-	Apr	2	2:00s	0	-
-Rule	AS	2007	only	-	Mar	lastSun	2:00s	0	-
-Rule	AS	2008	max	-	Apr	Sun>=1	2:00s	0	-
-Rule	AS	2008	max	-	Oct	Sun>=1	2:00s	1:00	-
+Rule	AS	1971	1985	-	Oct	lastSun	2:00s	1:00	D
+Rule	AS	1986	only	-	Oct	19	2:00s	1:00	D
+Rule	AS	1987	2007	-	Oct	lastSun	2:00s	1:00	D
+Rule	AS	1972	only	-	Feb	27	2:00s	0	S
+Rule	AS	1973	1985	-	Mar	Sun>=1	2:00s	0	S
+Rule	AS	1986	1990	-	Mar	Sun>=15	2:00s	0	S
+Rule	AS	1991	only	-	Mar	3	2:00s	0	S
+Rule	AS	1992	only	-	Mar	22	2:00s	0	S
+Rule	AS	1993	only	-	Mar	7	2:00s	0	S
+Rule	AS	1994	only	-	Mar	20	2:00s	0	S
+Rule	AS	1995	2005	-	Mar	lastSun	2:00s	0	S
+Rule	AS	2006	only	-	Apr	2	2:00s	0	S
+Rule	AS	2007	only	-	Mar	lastSun	2:00s	0	S
+Rule	AS	2008	max	-	Apr	Sun>=1	2:00s	0	S
+Rule	AS	2008	max	-	Oct	Sun>=1	2:00s	1:00	D
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Australia/Adelaide	9:14:20 -	LMT	1895 Feb
-			9:00	-	CST	1899 May
-			9:30	Aus	CST	1971
-			9:30	AS	CST
+			9:00	-	ACST	1899 May
+			9:30	Aus	AC%sT	1971
+			9:30	AS	AC%sT
 
 # Tasmania
 #
@@ -105,106 +105,106 @@ Zone Australia/Adelaide	9:14:20 -	LMT	1895 Feb
 # says King Island didn't observe DST from WWII until late 1971.
 #
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	AT	1967	only	-	Oct	Sun>=1	2:00s	1:00	-
-Rule	AT	1968	only	-	Mar	lastSun	2:00s	0	-
-Rule	AT	1968	1985	-	Oct	lastSun	2:00s	1:00	-
-Rule	AT	1969	1971	-	Mar	Sun>=8	2:00s	0	-
-Rule	AT	1972	only	-	Feb	lastSun	2:00s	0	-
-Rule	AT	1973	1981	-	Mar	Sun>=1	2:00s	0	-
-Rule	AT	1982	1983	-	Mar	lastSun	2:00s	0	-
-Rule	AT	1984	1986	-	Mar	Sun>=1	2:00s	0	-
-Rule	AT	1986	only	-	Oct	Sun>=15	2:00s	1:00	-
-Rule	AT	1987	1990	-	Mar	Sun>=15	2:00s	0	-
-Rule	AT	1987	only	-	Oct	Sun>=22	2:00s	1:00	-
-Rule	AT	1988	1990	-	Oct	lastSun	2:00s	1:00	-
-Rule	AT	1991	1999	-	Oct	Sun>=1	2:00s	1:00	-
-Rule	AT	1991	2005	-	Mar	lastSun	2:00s	0	-
-Rule	AT	2000	only	-	Aug	lastSun	2:00s	1:00	-
-Rule	AT	2001	max	-	Oct	Sun>=1	2:00s	1:00	-
-Rule	AT	2006	only	-	Apr	Sun>=1	2:00s	0	-
-Rule	AT	2007	only	-	Mar	lastSun	2:00s	0	-
-Rule	AT	2008	max	-	Apr	Sun>=1	2:00s	0	-
+Rule	AT	1967	only	-	Oct	Sun>=1	2:00s	1:00	D
+Rule	AT	1968	only	-	Mar	lastSun	2:00s	0	S
+Rule	AT	1968	1985	-	Oct	lastSun	2:00s	1:00	D
+Rule	AT	1969	1971	-	Mar	Sun>=8	2:00s	0	S
+Rule	AT	1972	only	-	Feb	lastSun	2:00s	0	S
+Rule	AT	1973	1981	-	Mar	Sun>=1	2:00s	0	S
+Rule	AT	1982	1983	-	Mar	lastSun	2:00s	0	S
+Rule	AT	1984	1986	-	Mar	Sun>=1	2:00s	0	S
+Rule	AT	1986	only	-	Oct	Sun>=15	2:00s	1:00	D
+Rule	AT	1987	1990	-	Mar	Sun>=15	2:00s	0	S
+Rule	AT	1987	only	-	Oct	Sun>=22	2:00s	1:00	D
+Rule	AT	1988	1990	-	Oct	lastSun	2:00s	1:00	D
+Rule	AT	1991	1999	-	Oct	Sun>=1	2:00s	1:00	D
+Rule	AT	1991	2005	-	Mar	lastSun	2:00s	0	S
+Rule	AT	2000	only	-	Aug	lastSun	2:00s	1:00	D
+Rule	AT	2001	max	-	Oct	Sun>=1	2:00s	1:00	D
+Rule	AT	2006	only	-	Apr	Sun>=1	2:00s	0	S
+Rule	AT	2007	only	-	Mar	lastSun	2:00s	0	S
+Rule	AT	2008	max	-	Apr	Sun>=1	2:00s	0	S
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Australia/Hobart	9:49:16	-	LMT	1895 Sep
-			10:00	-	EST	1916 Oct 1 2:00
-			10:00	1:00	EST	1917 Feb
-			10:00	Aus	EST	1967
-			10:00	AT	EST
+			10:00	-	AEST	1916 Oct 1 2:00
+			10:00	1:00	AEDT	1917 Feb
+			10:00	Aus	AE%sT	1967
+			10:00	AT	AE%sT
 Zone Australia/Currie	9:35:28	-	LMT	1895 Sep
-			10:00	-	EST	1916 Oct 1 2:00
-			10:00	1:00	EST	1917 Feb
-			10:00	Aus	EST	1971 Jul
-			10:00	AT	EST
+			10:00	-	AEST	1916 Oct 1 2:00
+			10:00	1:00	AEDT	1917 Feb
+			10:00	Aus	AE%sT	1971 Jul
+			10:00	AT	AE%sT
 
 # Victoria
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	AV	1971	1985	-	Oct	lastSun	2:00s	1:00	-
-Rule	AV	1972	only	-	Feb	lastSun	2:00s	0	-
-Rule	AV	1973	1985	-	Mar	Sun>=1	2:00s	0	-
-Rule	AV	1986	1990	-	Mar	Sun>=15	2:00s	0	-
-Rule	AV	1986	1987	-	Oct	Sun>=15	2:00s	1:00	-
-Rule	AV	1988	1999	-	Oct	lastSun	2:00s	1:00	-
-Rule	AV	1991	1994	-	Mar	Sun>=1	2:00s	0	-
-Rule	AV	1995	2005	-	Mar	lastSun	2:00s	0	-
-Rule	AV	2000	only	-	Aug	lastSun	2:00s	1:00	-
-Rule	AV	2001	2007	-	Oct	lastSun	2:00s	1:00	-
-Rule	AV	2006	only	-	Apr	Sun>=1	2:00s	0	-
-Rule	AV	2007	only	-	Mar	lastSun	2:00s	0	-
-Rule	AV	2008	max	-	Apr	Sun>=1	2:00s	0	-
-Rule	AV	2008	max	-	Oct	Sun>=1	2:00s	1:00	-
+Rule	AV	1971	1985	-	Oct	lastSun	2:00s	1:00	D
+Rule	AV	1972	only	-	Feb	lastSun	2:00s	0	S
+Rule	AV	1973	1985	-	Mar	Sun>=1	2:00s	0	S
+Rule	AV	1986	1990	-	Mar	Sun>=15	2:00s	0	S
+Rule	AV	1986	1987	-	Oct	Sun>=15	2:00s	1:00	D
+Rule	AV	1988	1999	-	Oct	lastSun	2:00s	1:00	D
+Rule	AV	1991	1994	-	Mar	Sun>=1	2:00s	0	S
+Rule	AV	1995	2005	-	Mar	lastSun	2:00s	0	S
+Rule	AV	2000	only	-	Aug	lastSun	2:00s	1:00	D
+Rule	AV	2001	2007	-	Oct	lastSun	2:00s	1:00	D
+Rule	AV	2006	only	-	Apr	Sun>=1	2:00s	0	S
+Rule	AV	2007	only	-	Mar	lastSun	2:00s	0	S
+Rule	AV	2008	max	-	Apr	Sun>=1	2:00s	0	S
+Rule	AV	2008	max	-	Oct	Sun>=1	2:00s	1:00	D
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Australia/Melbourne 9:39:52 -	LMT	1895 Feb
-			10:00	Aus	EST	1971
-			10:00	AV	EST
+			10:00	Aus	AE%sT	1971
+			10:00	AV	AE%sT
 
 # New South Wales
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	AN	1971	1985	-	Oct	lastSun	2:00s	1:00	-
-Rule	AN	1972	only	-	Feb	27	2:00s	0	-
-Rule	AN	1973	1981	-	Mar	Sun>=1	2:00s	0	-
-Rule	AN	1982	only	-	Apr	Sun>=1	2:00s	0	-
-Rule	AN	1983	1985	-	Mar	Sun>=1	2:00s	0	-
-Rule	AN	1986	1989	-	Mar	Sun>=15	2:00s	0	-
-Rule	AN	1986	only	-	Oct	19	2:00s	1:00	-
-Rule	AN	1987	1999	-	Oct	lastSun	2:00s	1:00	-
-Rule	AN	1990	1995	-	Mar	Sun>=1	2:00s	0	-
-Rule	AN	1996	2005	-	Mar	lastSun	2:00s	0	-
-Rule	AN	2000	only	-	Aug	lastSun	2:00s	1:00	-
-Rule	AN	2001	2007	-	Oct	lastSun	2:00s	1:00	-
-Rule	AN	2006	only	-	Apr	Sun>=1	2:00s	0	-
-Rule	AN	2007	only	-	Mar	lastSun	2:00s	0	-
-Rule	AN	2008	max	-	Apr	Sun>=1	2:00s	0	-
-Rule	AN	2008	max	-	Oct	Sun>=1	2:00s	1:00	-
+Rule	AN	1971	1985	-	Oct	lastSun	2:00s	1:00	D
+Rule	AN	1972	only	-	Feb	27	2:00s	0	S
+Rule	AN	1973	1981	-	Mar	Sun>=1	2:00s	0	S
+Rule	AN	1982	only	-	Apr	Sun>=1	2:00s	0	S
+Rule	AN	1983	1985	-	Mar	Sun>=1	2:00s	0	S
+Rule	AN	1986	1989	-	Mar	Sun>=15	2:00s	0	S
+Rule	AN	1986	only	-	Oct	19	2:00s	1:00	D
+Rule	AN	1987	1999	-	Oct	lastSun	2:00s	1:00	D
+Rule	AN	1990	1995	-	Mar	Sun>=1	2:00s	0	S
+Rule	AN	1996	2005	-	Mar	lastSun	2:00s	0	S
+Rule	AN	2000	only	-	Aug	lastSun	2:00s	1:00	D
+Rule	AN	2001	2007	-	Oct	lastSun	2:00s	1:00	D
+Rule	AN	2006	only	-	Apr	Sun>=1	2:00s	0	S
+Rule	AN	2007	only	-	Mar	lastSun	2:00s	0	S
+Rule	AN	2008	max	-	Apr	Sun>=1	2:00s	0	S
+Rule	AN	2008	max	-	Oct	Sun>=1	2:00s	1:00	D
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Australia/Sydney	10:04:52 -	LMT	1895 Feb
-			10:00	Aus	EST	1971
-			10:00	AN	EST
+			10:00	Aus	AE%sT	1971
+			10:00	AN	AE%sT
 Zone Australia/Broken_Hill 9:25:48 -	LMT	1895 Feb
-			10:00	-	EST	1896 Aug 23
-			9:00	-	CST	1899 May
-			9:30	Aus	CST	1971
-			9:30	AN	CST	2000
-			9:30	AS	CST
+			10:00	-	AEST	1896 Aug 23
+			9:00	-	ACST	1899 May
+			9:30	Aus	AC%sT	1971
+			9:30	AN	AC%sT	2000
+			9:30	AS	AC%sT
 
 # Lord Howe Island
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	LH	1981	1984	-	Oct	lastSun	2:00	1:00	-
-Rule	LH	1982	1985	-	Mar	Sun>=1	2:00	0	-
-Rule	LH	1985	only	-	Oct	lastSun	2:00	0:30	-
-Rule	LH	1986	1989	-	Mar	Sun>=15	2:00	0	-
-Rule	LH	1986	only	-	Oct	19	2:00	0:30	-
-Rule	LH	1987	1999	-	Oct	lastSun	2:00	0:30	-
-Rule	LH	1990	1995	-	Mar	Sun>=1	2:00	0	-
-Rule	LH	1996	2005	-	Mar	lastSun	2:00	0	-
-Rule	LH	2000	only	-	Aug	lastSun	2:00	0:30	-
-Rule	LH	2001	2007	-	Oct	lastSun	2:00	0:30	-
-Rule	LH	2006	only	-	Apr	Sun>=1	2:00	0	-
-Rule	LH	2007	only	-	Mar	lastSun	2:00	0	-
-Rule	LH	2008	max	-	Apr	Sun>=1	2:00	0	-
-Rule	LH	2008	max	-	Oct	Sun>=1	2:00	0:30	-
+Rule	LH	1981	1984	-	Oct	lastSun	2:00	1:00	D
+Rule	LH	1982	1985	-	Mar	Sun>=1	2:00	0	S
+Rule	LH	1985	only	-	Oct	lastSun	2:00	0:30	D
+Rule	LH	1986	1989	-	Mar	Sun>=15	2:00	0	S
+Rule	LH	1986	only	-	Oct	19	2:00	0:30	D
+Rule	LH	1987	1999	-	Oct	lastSun	2:00	0:30	D
+Rule	LH	1990	1995	-	Mar	Sun>=1	2:00	0	S
+Rule	LH	1996	2005	-	Mar	lastSun	2:00	0	S
+Rule	LH	2000	only	-	Aug	lastSun	2:00	0:30	D
+Rule	LH	2001	2007	-	Oct	lastSun	2:00	0:30	D
+Rule	LH	2006	only	-	Apr	Sun>=1	2:00	0	S
+Rule	LH	2007	only	-	Mar	lastSun	2:00	0	S
+Rule	LH	2008	max	-	Apr	Sun>=1	2:00	0	S
+Rule	LH	2008	max	-	Oct	Sun>=1	2:00	0:30	D
 Zone Australia/Lord_Howe 10:36:20 -	LMT	1895 Feb
-			10:00	-	EST	1981 Mar
-			10:30	LH	LHST
+			10:00	-	AEST	1981 Mar
+			10:30	LH	LH%sT
 
 # Australian miscellany
 #
@@ -236,12 +236,12 @@ Zone Australia/Lord_Howe 10:36:20 -	LMT	1895 Feb
 # this is required for correct handling of times before 1916 by
 # pre-2013 versions of localtime.
 Zone Antarctica/Macquarie 0	-	zzz	1899 Nov
-			10:00	-	EST	1916 Oct 1 2:00
-			10:00	1:00	EST	1917 Feb
-			10:00	Aus	EST	1919 Apr 1 0:00s
+			10:00	-	AEST	1916 Oct 1 2:00
+			10:00	1:00	AEDT	1917 Feb
+			10:00	Aus	AE%sT	1919 Apr 1 0:00s
 			0	-	zzz	1948 Mar 25
-			10:00	Aus	EST	1967
-			10:00	AT	EST	2010 Apr 4 3:00
+			10:00	Aus	AE%sT	1967
+			10:00	AT	AE%sT	2010 Apr 4 3:00
 			11:00	-	MIST	# Macquarie I Standard Time
 
 # Christmas
@@ -802,21 +802,21 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # I invented the abbreviations marked '*' in the following table;
 # the rest are from earlier versions of this file, or from other sources.
 # Corrections are welcome!
-#		std dst
-#		LMT	Local Mean Time
-#	  8:00	WST WST	Western Australia
-#	  8:45	CWST CWST Central Western Australia*
-#	  9:00	JST	Japan
-#	  9:30	CST CST	Central Australia
-#	 10:00	EST EST	Eastern Australia
-#	 10:00	ChST	Chamorro
-#	 10:30	LHST LHST Lord Howe*
-#	 11:30	NZMT NZST New Zealand through 1945
-#	 12:00	NZST NZDT New Zealand 1946-present
-#	 12:45	CHAST CHADT Chatham*
-#	-11:00	SST	Samoa
-#	-10:00	HST	Hawaii
-#	- 8:00	PST	Pitcairn*
+#		std	dst
+#		LMT		Local Mean Time
+#	  8:00	AWST	AWDT	Western Australia
+#	  8:45	ACWST	ACWDT	Central Western Australia*
+#	  9:00	JST		Japan
+#	  9:30	ACST	ACDT	Central Australia
+#	 10:00	AEST	AEDT	Eastern Australia
+#	 10:00	ChST		Chamorro
+#	 10:30	LHST	LHDT	Lord Howe*
+#	 11:30	NZMT	NZST	New Zealand through 1945
+#	 12:00	NZST	NZDT	New Zealand 1946-present
+#	 12:45	CHAST	CHADT	Chatham*
+#	-11:00	SST		Samoa
+#	-10:00	HST		Hawaii
+#	- 8:00	PST		Pitcairn*
 #
 # See the 'northamerica' file for Hawaii.
 # See the 'southamerica' file for Easter I and the Galápagos Is.
@@ -825,6 +825,19 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 
 # Australia
 
+# From Paul Eggert (2014-06-30):
+# Daylight saving time has long been controversial in Australia, pitting
+# region against region, rural against urban, and local against global.
+# For example, in her review of Graeme Davison's _The Unforgiving
+# Minute: how Australians learned to tell the time_ (1993), Perth native
+# Phillipa J Martyr wrote, "The section entitled 'Saving Daylight' was
+# very informative, but was (as can, sadly, only be expected from a
+# Melbourne-based study) replete with the usual chuckleheaded
+# Queenslanders and straw-chewing yokels from the West prattling fables
+# about fading curtains and crazed farm animals."
+# Electronic Journal of Australian and New Zealand History (1997-03-03)
+# http://www.jcu.edu.au/aff/history/reviews/davison.htm
+
 # From Paul Eggert (2005-12-08):
 # Implementation Dates of Daylight Saving Time within Australia
 # <http://www.bom.gov.au/climate/averages/tables/dst_times.shtml>
@@ -853,98 +866,105 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # prefixed by the word 'Australian' when referring to local times;
 # time announcements on that service, naturally enough, are made in UTC.
 
-# From Arthur David Olson (1992-03-08):
-# Given the above, what's chosen for year-round use is:
-#	CST	for any place operating at a GMTOFF of 9:30
-#	WST	for any place operating at a GMTOFF of 8:00
-#	EST	for any place operating at a GMTOFF of 10:00
-
-# From Chuck Soper (2006-06-01):
-# I recently found this Australian government web page on time zones:
-# <http://www.australia.gov.au/about-australia-13time>
-# And this government web page lists time zone names and abbreviations:
-# <http://www.bom.gov.au/climate/averages/tables/daysavtm.shtml>
-
-# From Paul Eggert (2001-04-05), summarizing a long discussion about "EST"
-# versus "AEST" etc.:
-#
-# I see the following points of dispute:
-#
-# * How important are unique time zone abbreviations?
-#
-#   Here I tend to agree with the point (most recently made by Chris
-#   Newman) that unique abbreviations should not be essential for proper
-#   operation of software.  We have other instances of ambiguity
-#   (e.g. "IST" denoting both "Israel Standard Time" and "Indian
-#   Standard Time"), and they are not likely to go away any time soon.
-#   In the old days, some software mistakenly relied on unique
-#   abbreviations, but this is becoming less true with time, and I don't
-#   think it's that important to cater to such software these days.
-#
-#   On the other hand, there is another motivation for unambiguous
-#   abbreviations: it cuts down on human confusion.  This is
-#   particularly true for Australia, where "EST" can mean one thing for
-#   time T and a different thing for time T plus 1 second.
-#
-# * Does the relevant legislation indicate which abbreviations should be used?
-#
-#   Here I tend to think that things are a mess, just as they are in
-#   many other countries.  We Americans are currently disagreeing about
-#   which abbreviation to use for the newly legislated Chamorro Standard
-#   Time, for example.
-#
-#   Personally, I would prefer to use common practice; I would like to
-#   refer to legislation only for examples of common practice, or as a
-#   tiebreaker.
-#
-# * Do Australians more often use "Eastern Daylight Time" or "Eastern
-#   Summer Time"?  Do they typically prefix the time zone names with
-#   the word "Australian"?
-#
-#   My own impression is that both "Daylight Time" and "Summer Time" are
-#   common and are widely understood, but that "Summer Time" is more
-#   popular; and that the leading "A" is also common but is omitted more
-#   often than not.  I just used AltaVista advanced search and got the
-#   following count of page hits:
-#
-#     1,103 "Eastern Summer Time" AND domain:au
-#       971 "Australian Eastern Summer Time" AND domain:au
-#       613 "Eastern Daylight Time" AND domain:au
-#       127 "Australian Eastern Daylight Time" AND domain:au
-#
-#   Here "Summer" seems quite a bit more popular than "Daylight",
-#   particularly when we know the time zone is Australian and not US,
-#   say.  The "Australian" prefix seems to be popular for Eastern Summer
-#   Time, but unpopular for Eastern Daylight Time.
-#
-#   For abbreviations, tools like AltaVista are less useful because of
-#   ambiguity.  Many hits are not really time zones, unfortunately, and
-#   many hits denote US time zones and not Australian ones.  But here
-#   are the hit counts anyway:
-#
-#     161,304 "EST" and domain:au
-#      25,156 "EDT" and domain:au
-#      18,263 "AEST" and domain:au
-#      10,416 "AEDT" and domain:au
-#
-#      14,538 "CST" and domain:au
-#       5,728 "CDT" and domain:au
-#         176 "ACST" and domain:au
-#          29 "ACDT" and domain:au
-#
-#       7,539 "WST" and domain:au
-#          68 "AWST" and domain:au
-#
-#   This data suggest that Australians tend to omit the "A" prefix in
-#   practice.  The situation for "ST" versus "DT" is less clear, given
-#   the ambiguities involved.
-#
-# * How do Australians feel about the abbreviations in the tz database?
-#
-#   If you just count Australians on this list, I count 2 in favor and 3
-#   against.  One of the "against" votes (David Keegel) counseled delay,
-#   saying that both AEST/AEDT and EST/EST are widely used and
-#   understood in Australia.
+# From Paul Eggert (2014-06-30):
+#
+# Inspired by Mackin's remarks quoted above, earlier versions of this
+# file used "EST" for both Eastern Standard Time and Eastern Summer
+# Time in Australia, and similarly for "CST", "CWST", and "WST".
+# However, these abbreviations were confusing and were not common
+# practice among Australians, and there were justifiable complaints
+# about them, so I attempted to survey current Australian usage.
+# For the tz database, the full English phrase is not that important;
+# what matters is the abbreviation.  It's difficult to survey the web
+# directly for abbreviation usage, as there are so many false hits for
+# strings like "EST" and "EDT", so I looked for pages that defined an
+# abbreviation for eastern or central DST in Australia, and got the
+# following numbers of unique hits for the listed Google queries:
+#
+#   10 "Eastern Daylight Time AEST" site:au [some are false hits]
+#   10 "Eastern Summer Time AEST" site:au
+#   10 "Summer Time AEDT" site:au
+#   13 "EDST Eastern Daylight Saving Time" site:au
+#   18 "Summer Time ESST" site:au
+#   28 "Eastern Daylight Saving Time EDST" site:au
+#   39 "EDT Eastern Daylight Time" site:au [some are false hits]
+#   53 "Eastern Daylight Time EDT" site:au [some are false hits]
+#   54 "AEDT Australian Eastern Daylight Time" site:au
+#  182 "Eastern Daylight Time AEDT" site:au
+#
+#   17 "Central Daylight Time CDT" site:au [some are false hits]
+#   46 "Central Daylight Time ACDT" site:au
+#
+# I tried several other variants (e.g., "Eastern Summer Time EST") but
+# they all returned fewer than 10 unique hits.  I also looked for pages
+# mentioning both "western standard time" and an abbreviation, since
+# there is no WST in the US to generate false hits, and found:
+#
+#  156 "western standard time" AWST site:au
+#  226 "western standard time" WST site:au
+#
+# I then surveyed the top ten newspapers in Australia by circulation as
+# listed in Wikipedia, using Google queries like "AEDT site:heraldsun.com.au"
+# and obtaining estimated counts from the initial page of search results.
+# All ten papers greatly preferred "AEDT" to "EDT".  The papers
+# surveyed were the Herald Sun, The Daily Telegraph, The Courier-Mail,
+# The Sydney Morning Herald, The West Australian, The Age, The Advertiser,
+# The Australian, The Financial Review, and The Herald (Newcastle).
+#
+# I also searched for historical usage, to see whether abbreviations
+# like "AEDT" are new.  A Trove search <http://trove.nla.gov.au/>
+# found only one newspaper (The Canberra Times) with a house style
+# dating back to the 1970s, I expect because other newspapers weren't
+# fully indexed.  The Canberra Times strongly preferred abbreviations
+# like "AEDT".  The first occurrence of "AEDT" was a World Weather
+# column (1971-11-17, page 24), and of "ACDT" was a Scoreboard column
+# (1993-01-24, p 16).  The style was the typical usage but was not
+# strictly enforced; for example, "Welcome to the twilight zones ..."
+# (1994-10-29, p 1) uses the abbreviations AEST/AEDT, CST/CDT, and
+# WST, and goes on to say, "The confusion and frustration some feel
+# about the lack of uniformity among Australia's six states and two
+# territories has prompted one group to form its very own political
+# party -- the Sydney-based Daylight Saving Extension Party."
+#
+# I also surveyed federal government sources.  They did not agree:
+#
+#   The Australian Government (2014-03-26)
+#   http://australia.gov.au/about-australia/our-country/time
+#   (This document was produced by the Department of Finance.)
+#   AEST ACST AWST AEDT ACDT
+#
+#   Bureau of Meteorology (2012-11-08)
+#   http://www.bom.gov.au/climate/averages/tables/daysavtm.shtml
+#   EST CST WST EDT CDT
+#
+#   Civil Aviation Safety Authority (undated)
+#   http://services.casa.gov.au/outnback/inc/pages/episode3/episode-3_time_zones.shtml
+#   EST CST WST (no abbreviations given for DST)
+#
+#   Geoscience Australia (2011-11-24)
+#   http://www.ga.gov.au/geodesy/astro/sunrise.jsp
+#   AEST ACST AWST AEDT ACDT
+#
+#   Parliamentary Library (2008-11-10)
+#   http://www.aph.gov.au/binaries/library/pubs/rp/2008-09/09rp14.pdf
+#   EST CST WST preferred for standard time; AEST AEDT ACST ACDT also used
+#
+#   The Transport Safety Bureau has an extensive series of accident reports,
+#   and investigators seem to use whatever abbreviation they like.
+#   Googling site:atsb.gov.au found the following number of unique hits:
+#   311 "ESuT", 195 "EDT", 26 "AEDT", 83 "CSuT", 46 "CDT".
+#   "_SuT" tended to appear in older reports, and "A_DT" tended to
+#   appear in reports of events with international implications.
+#
+# From the above it appears that there is a working consensus in
+# Australia to use trailing "DT" for daylight saving time; although
+# some sources use trailing "SST" or "ST" or "SuT" they are by far in
+# the minority.  The case for leading "A" is weaker, but since it
+# seems to be preferred in the overall web and is preferred in all
+# the leading newspaper websites and in many government departments,
+# it has a stronger case than omitting the leading "A".  The current
+# version of the database therefore uses abbreviations like "AEST" and
+# "AEDT" for Australian time zones.
 
 # From Paul Eggert (1995-12-19):
 # Shanks & Pottenger report 2:00 for all autumn changes in Australia and NZ.
-- 
1.9.1


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