Radio Santa María (Coyhaique) reported Wednesday (in Spanish)[1] of a
delay in the decision whether Chile’s Aysén Region will switch from
-04/-03 (with DST) to all-year -03. A government representative denied
that the delay is due to Interior Minister Carolina Tohá’s resignation
Tuesday to run for president, and Tohá’s replacement that day by Álvaro
Elizalde.
If the Interior Ministry decides to go ahead with the change, this would
invalidate current TZDB for Aysén at some future point. A plausible time
for this would be April 5 at 24:00, which is short notice for people
responsible for operating systems in the region. Perhaps someone with
connections in Chile could suggest making any change in April 2026
rather than this year.
The attached hypothetical patch shows one way that this might play out
in four weeks. I have not installed this patch into the TZDB development
repository, though, as the situation is too iffy.
[1]:
https://www.radiosantamaria.cl/2025/03/05/regional-huso-horario-anunciaran-en-los-proximos-dias-si-continuara-o-no-con-el-horario-de-verano/
From 4b04521a74bede4e46fbec00683405f1fa9df47d Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 8 Mar 2025 18:39:59 -0800
Subject: [HYPOTHETICAL] =?UTF-8?q?New=20Zone=20America/Coyhaique=20for=20A?=
=?UTF-8?q?ys=C3=A9n=20Region?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
* NEWS: Mention this.
* southamerica, zone.tab, zone1970.tab, zonenow.tab:
(America/Coyhaique): New Zone, which acts like America/Punta_Arenas
except it switches to -03 on 2025-04-06 not 2016-12-04.
---
NEWS | 6 ++++++
southamerica | 14 ++++++++++++++
zone.tab | 1 +
zone1970.tab | 1 +
zonenow.tab | 2 ++
5 files changed, 24 insertions(+)
diff --git a/NEWS b/NEWS
index eec41543..87ba7865 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,12 @@ News for the tz database
Unreleased, experimental changes
+ Changes to data
+
+ Chile's Aysén Region now observes -03 all year, not -04 in winter
+ and -03 in summer. A new Zone America/Coyhaique splits from
+ America/Santiago.
+
Changes to code
'zic -l TIMEZONE -d . -l /some/other/file/system' no longer has a
diff --git a/southamerica b/southamerica
index 1fcf6514..cddec360 100644
--- a/southamerica
+++ b/southamerica
@@ -1371,6 +1371,20 @@ Zone America/Santiago -4:42:45 - LMT 1890
-5:00 1:00 %z 1947 Mar 31 24:00
-5:00 - %z 1947 May 21 23:00
-4:00 Chile %z
+Zone America/Coyhaique -4:48:16 - LMT 1890
+ -4:42:45 - SMT 1910 Jan 10
+ -5:00 - %z 1916 Jul 1
+ -4:42:45 - SMT 1918 Sep 10
+ -4:00 - %z 1919 Jul 1
+ -4:42:45 - SMT 1927 Sep 1
+ -5:00 Chile %z 1932 Sep 1
+ -4:00 - %z 1942 Jun 1
+ -5:00 - %z 1942 Aug 1
+ -4:00 - %z 1946 Aug 28 24:00
+ -5:00 1:00 %z 1947 Mar 31 24:00
+ -5:00 - %z 1947 May 21 23:00
+ -4:00 Chile %z 2025 Apr 6
+ -3:00 - %z
Zone America/Punta_Arenas -4:43:40 - LMT 1890
-4:42:45 - SMT 1910 Jan 10
-5:00 - %z 1916 Jul 1
diff --git a/zone.tab b/zone.tab
index be4f7ba2..2626b055 100644
--- a/zone.tab
+++ b/zone.tab
@@ -139,6 +139,7 @@ CH +4723+00832 Europe/Zurich
CI +0519-00402 Africa/Abidjan
CK -2114-15946 Pacific/Rarotonga
CL -3327-07040 America/Santiago most of Chile
+CL -4534-07204 America/Coyhaique Aysen Region
CL -5309-07055 America/Punta_Arenas Magallanes Region
CL -2709-10926 Pacific/Easter Easter Island
CM +0403+00942 Africa/Douala
diff --git a/zone1970.tab b/zone1970.tab
index 03ffe7c1..36535bdf 100644
--- a/zone1970.tab
+++ b/zone1970.tab
@@ -124,6 +124,7 @@ CH,DE,LI +4723+00832 Europe/Zurich Büsingen
CI,BF,GH,GM,GN,IS,ML,MR,SH,SL,SN,TG +0519-00402 Africa/Abidjan
CK -2114-15946 Pacific/Rarotonga
CL -3327-07040 America/Santiago most of Chile
+CL -4534-07204 America/Coyhaique Aysén Region
CL -5309-07055 America/Punta_Arenas Magallanes Region
CL -2709-10926 Pacific/Easter Easter Island
CN +3114+12128 Asia/Shanghai Beijing Time
diff --git a/zonenow.tab b/zonenow.tab
index d2c1e485..6aa41678 100644
--- a/zonenow.tab
+++ b/zonenow.tab
@@ -96,6 +96,8 @@ XX +1828-06954 America/Santo_Domingo Atlantic Standard ("AST") - eastern Caribbe
#
# -04/-03 (Chile DST)
XX -3327-07040 America/Santiago most of Chile
+# -04/-03 (Chile DST) until 2025-04-06; then -03
+XX -4534-07204 America/Coyhaique Aysén Region
#
# -04/-03 - AST/ADT (North America DST)
XX +4439-06336 America/Halifax Atlantic ("AST/ADT") - Canada; Bermuda
--
2.45.2
