Give British Columbia, Alberta and Manitoba their own timezones

British Columbia, Alberta and Manitoba stop changing their clocks in
November 2026 and stay on UTC-7, UTC-6 and UTC-5 all year. The "US &
Canada" entries they use today go back an hour in winter, so each
province gets its own entry: Vancouver, Edmonton and Winnipeg.
`Canada/Central` follows Manitoba's rules, so it can no longer stand in
for US Central time or for Central America, which stays on UTC-6;
"Central America" moves to `America/Guatemala`.

`ubuntu-latest` now resolves to Ubuntu 26.04, whose system zone files
leave out the legacy `US/*` names, so the suite failed at collection with
"Invalid timezone US/Hawaii". tox now installs `tzdata`, which
`zoneinfo` falls back to for names the system does not have.

Author: gil-doesit

CHANGELOG.md

@@ -5,6 +5,15 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- Add `America/Vancouver`, since British Columbia stays on UTC-7 all year from November 2026.
+- Add `America/Edmonton` and `America/Winnipeg`, since Alberta and Manitoba stay on UTC-6 and UTC-5 all year from November 2026.
+
+### Changed
+- "Central America" uses `America/Guatemala` instead of `Canada/Central`, which follows Manitoba's rules.
+
+### Removed
+- Drop the `Canada/Central` entry labeled "Central Time (US & Canada)". `US/Central` covers the US, and `America/Winnipeg` covers Manitoba.
 
 ## [3.0.0] - 2024-11-15
 ### Changed

timezones/_defs.py

@@ -31,11 +31,12 @@
     ("US/Arizona", "Arizona"),
     ("America/Mazatlan", "Mazatlan"),
     ("US/Mountain", "Mountain Time (US & Canada)"),
+    ("America/Vancouver", "Vancouver"),
     # -06
     ("America/Chihuahua", "Chihuahua"),
     ("US/Central", "Central Time (US & Canada)"),
-    ("Canada/Central", "Central America"),
-    ("Canada/Central", "Central Time (US & Canada)"),
+    ("America/Guatemala", "Central America"),
+    ("America/Edmonton", "Edmonton"),
     ("Mexico/General", "Guadalajara"),
     ("Mexico/General", "Mexico City"),
     ("America/Monterrey", "Monterrey"),
@@ -47,6 +48,7 @@
     ("America/Lima", "Lima"),
     ("America/Rio_Branco", "Rio Branco"),
     ("Etc/GMT+5", "Quito"),  # "plus" value is correct!
+    ("America/Winnipeg", "Winnipeg"),
     # -04
     ("America/Caracas", "Caracas"),
     ("Canada/Atlantic", "Atlantic Time (Canada)"),

timezones/test_timezones.py

@@ -1,3 +1,5 @@
+from datetime import datetime, timedelta
+
 import pytest
 
 from . import _defs, tz_rendering, tz_utils, zones
@@ -74,3 +76,80 @@ def test_aliases(tzname):
     _, name, formatted = tz_utils.format_tz_by_name(tzname)
     assert name == tzname
     assert tzname in formatted
+
+
+def test_get_timezones_lists_vancouver():
+    # Given British Columbia has its own timezone from November 2026
+    vancouver_labels = []
+
+    # When the supported timezones are listed
+    all_timezones = zones.get_timezones()
+
+    # Then America/Vancouver is offered under its own name
+    for offset_str, tzname, verbose_name in all_timezones:
+        if tzname == "America/Vancouver":
+            vancouver_labels.append(verbose_name)
+    assert len(vancouver_labels) == 1
+    assert vancouver_labels[0].endswith(") Vancouver")
+
+
+def test_get_timezones_lists_edmonton():
+    # Given Alberta has its own timezone from November 2026
+    edmonton_labels = []
+
+    # When the supported timezones are listed
+    all_timezones = zones.get_timezones()
+
+    # Then America/Edmonton is offered under its own name
+    for offset_str, tzname, verbose_name in all_timezones:
+        if tzname == "America/Edmonton":
+            edmonton_labels.append(verbose_name)
+    assert len(edmonton_labels) == 1
+    assert edmonton_labels[0].endswith(") Edmonton")
+
+
+def test_get_timezones_lists_winnipeg():
+    # Given Manitoba has its own timezone from November 2026
+    winnipeg_labels = []
+
+    # When the supported timezones are listed
+    all_timezones = zones.get_timezones()
+
+    # Then America/Winnipeg is offered under its own name
+    for offset_str, tzname, verbose_name in all_timezones:
+        if tzname == "America/Winnipeg":
+            winnipeg_labels.append(verbose_name)
+    assert len(winnipeg_labels) == 1
+    assert winnipeg_labels[0].endswith(") Winnipeg")
+
+
+def test_get_timezones_offers_us_central_time_only_for_us_central():
+    # Given Manitoba no longer follows US Central time from November 2026
+    central_time_zone_names = []
+
+    # When the supported timezones are listed
+    all_timezones = zones.get_timezones()
+
+    # Then "Central Time (US & Canada)" is offered only for US/Central
+    for offset_str, tzname, verbose_name in all_timezones:
+        if verbose_name.endswith(") Central Time (US & Canada)"):
+            central_time_zone_names.append(tzname)
+    assert central_time_zone_names == ["US/Central"]
+
+
+def test_get_timezones_keeps_central_america_on_utc_minus_6():
+    # Given a date in December 2026, after Manitoba stops changing its clocks
+    december_2026 = datetime(2026, 12, 1, 12, 0)
+    central_america_zone_names = []
+
+    # When the supported timezones are listed
+    all_timezones = zones.get_timezones()
+
+    # Then "Central America" is offered once, on a zone that is at UTC-6 then
+    for offset_str, tzname, verbose_name in all_timezones:
+        if verbose_name.endswith(") Central America"):
+            central_america_zone_names.append(tzname)
+    assert len(central_america_zone_names) == 1
+    central_america_zone = tz_utils.get_timezone(central_america_zone_names[0])
+    assert central_america_zone is not None
+    assert central_america_zone.utcoffset(december_2026) == timedelta(hours=-6)

tox.ini

@@ -11,6 +11,7 @@ python =
 [testenv]
 deps =
     pytest
+    tzdata
 commands =
     pytest {posargs}