[tz] [PROPOSED PATCH 3/4] Phase out alphanumeric abbrs from etcetera

Paul Eggert eggert at cs.ucla.edu
Tue Aug 23 23:55:44 UTC 2016


* NEWS: Document this.
* etcetera (Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11)
(Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6)
(Etc/GMT-5, Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1)
(Etc/GMT+2, Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7)
(Etc/GMT+8, Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12):
Use numeric time zone abbreviations, for consistency with the rest
of the database.  The old abbreviations like "GMT-9" were both
confusing and obsolete.
---
 NEWS     | 21 ++++++++++++------
 etcetera | 74 +++++++++++++++++++++++++++++++---------------------------------
 2 files changed, 50 insertions(+), 45 deletions(-)

diff --git a/NEWS b/NEWS
index d88d2bb..71916a9 100644
--- a/NEWS
+++ b/NEWS
@@ -15,9 +15,11 @@ Unreleased, experimental changes
 
   Changes to past and future time zone abbreviations
 
-    Several zones in Antarctica and the former Soviet Union now use
-    numeric time zone abbreviations instead of invented ones.  The
-    affected zones are Antarctica/Casey, Antarctica/Davis,
+    Several zones in Antarctica and the former Soviet Union, along
+    with zones intended for ships at sea that cannot use POSIX TZ
+    strings, now use numeric time zone abbreviations instead of
+    invented or obsolete alphanumeric abbreviations.  The affected
+    zones are Antarctica/Casey, Antarctica/Davis,
     Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
     Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
     Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
@@ -25,10 +27,15 @@ Unreleased, experimental changes
     Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
     Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
     Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
-    Asia/Yerevan, Europe/Kaliningrad, Europe/Minsk, Europe/Samara,
-    Europe/Volgograd, and Indian/Kerguelen.  For Europe/Moscow the
-    invented abbreviation MSM was replaced by +05, whereas MSK and MSD
-    were kept as they are not our invention and are widely used.
+    Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
+    Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
+    Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
+    Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
+    Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
+    Europe/Minsk, Europe/Samara, Europe/Volgograd, and
+    Indian/Kerguelen.  For Europe/Moscow the invented abbreviation MSM
+    was replaced by +05, whereas MSK and MSD were kept as they are not
+    our invention and are widely used.
 
   Changes to code
 
diff --git a/etcetera b/etcetera
index c2e2532..f5fa4c9 100644
--- a/etcetera
+++ b/etcetera
@@ -8,6 +8,13 @@
 # need now for the entries that are not on UTC are for ships at sea
 # that cannot use POSIX TZ settings.
 
+# Starting with POSIX 1003.1-2001, the entries below are all
+# unnecessary as settings for the TZ environment variable.  E.g.,
+# instead of TZ='Etc/GMT+4' one can use the POSIX setting TZ='<-04>+4'.
+#
+# Do not use a POSIX TZ setting like TZ='GMT+4', which is four hours
+# behind GMT but uses the completely misleading abbreviation "GMT".
+
 Zone	Etc/GMT		0	-	GMT
 Zone	Etc/UTC		0	-	UTC
 Zone	Etc/UCT		0	-	UCT
@@ -26,23 +33,13 @@ Link	Etc/GMT				Etc/GMT-0
 Link	Etc/GMT				Etc/GMT+0
 Link	Etc/GMT				Etc/GMT0
 
-# We use POSIX-style signs in the Zone names and the output abbreviations,
+# Be consistent with POSIX TZ settings in the Zone names,
 # even though this is the opposite of what many people expect.
 # POSIX has positive signs west of Greenwich, but many people expect
 # positive signs east of Greenwich.  For example, TZ='Etc/GMT+4' uses
-# the abbreviation "GMT+4" and corresponds to 4 hours behind UT
+# the abbreviation "-04" and corresponds to 4 hours behind UT
 # (i.e. west of Greenwich) even though many people would expect it to
 # mean 4 hours ahead of UT (i.e. east of Greenwich).
-#
-# In the draft 5 of POSIX 1003.1-200x, the angle bracket notation allows for
-# TZ='<GMT-4>+4'; if you want time zone abbreviations conforming to
-# ISO 8601 you can use TZ='<-0400>+4'.  Thus the commonly-expected
-# offset is kept within the angle bracket (and is used for display)
-# while the POSIX sign is kept outside the angle bracket (and is used
-# for calculation).
-#
-# Do not use a TZ setting like TZ='GMT+4', which is four hours behind
-# GMT but uses the completely misleading abbreviation "GMT".
 
 # Earlier incarnations of this package were not POSIX-compliant,
 # and had lines such as
@@ -51,30 +48,31 @@ Link	Etc/GMT				Etc/GMT0
 # way does a
 #		zic -l GMT-12
 # so we moved the names into the Etc subdirectory.
+# Also, the time zone abbreviations are now compatible with %z.
 
-Zone	Etc/GMT-14	14	-	GMT-14	# 14 hours ahead of GMT
-Zone	Etc/GMT-13	13	-	GMT-13
-Zone	Etc/GMT-12	12	-	GMT-12
-Zone	Etc/GMT-11	11	-	GMT-11
-Zone	Etc/GMT-10	10	-	GMT-10
-Zone	Etc/GMT-9	9	-	GMT-9
-Zone	Etc/GMT-8	8	-	GMT-8
-Zone	Etc/GMT-7	7	-	GMT-7
-Zone	Etc/GMT-6	6	-	GMT-6
-Zone	Etc/GMT-5	5	-	GMT-5
-Zone	Etc/GMT-4	4	-	GMT-4
-Zone	Etc/GMT-3	3	-	GMT-3
-Zone	Etc/GMT-2	2	-	GMT-2
-Zone	Etc/GMT-1	1	-	GMT-1
-Zone	Etc/GMT+1	-1	-	GMT+1
-Zone	Etc/GMT+2	-2	-	GMT+2
-Zone	Etc/GMT+3	-3	-	GMT+3
-Zone	Etc/GMT+4	-4	-	GMT+4
-Zone	Etc/GMT+5	-5	-	GMT+5
-Zone	Etc/GMT+6	-6	-	GMT+6
-Zone	Etc/GMT+7	-7	-	GMT+7
-Zone	Etc/GMT+8	-8	-	GMT+8
-Zone	Etc/GMT+9	-9	-	GMT+9
-Zone	Etc/GMT+10	-10	-	GMT+10
-Zone	Etc/GMT+11	-11	-	GMT+11
-Zone	Etc/GMT+12	-12	-	GMT+12
+Zone	Etc/GMT-14	14	-	+14
+Zone	Etc/GMT-13	13	-	+13
+Zone	Etc/GMT-12	12	-	+12
+Zone	Etc/GMT-11	11	-	+11
+Zone	Etc/GMT-10	10	-	+10
+Zone	Etc/GMT-9	9	-	+09
+Zone	Etc/GMT-8	8	-	+08
+Zone	Etc/GMT-7	7	-	+07
+Zone	Etc/GMT-6	6	-	+06
+Zone	Etc/GMT-5	5	-	+05
+Zone	Etc/GMT-4	4	-	+04
+Zone	Etc/GMT-3	3	-	+03
+Zone	Etc/GMT-2	2	-	+02
+Zone	Etc/GMT-1	1	-	+01
+Zone	Etc/GMT+1	-1	-	-01
+Zone	Etc/GMT+2	-2	-	-02
+Zone	Etc/GMT+3	-3	-	-03
+Zone	Etc/GMT+4	-4	-	-04
+Zone	Etc/GMT+5	-5	-	-05
+Zone	Etc/GMT+6	-6	-	-06
+Zone	Etc/GMT+7	-7	-	-07
+Zone	Etc/GMT+8	-8	-	-08
+Zone	Etc/GMT+9	-9	-	-09
+Zone	Etc/GMT+10	-10	-	-10
+Zone	Etc/GMT+11	-11	-	-11
+Zone	Etc/GMT+12	-12	-	-12
-- 
2.5.5



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