Give Alberta and Manitoba their own timezones

Alberta and Manitoba stop changing their clocks in November 2026, like
British Columbia, so "Mountain Time (US & Canada)" and "Central Time (US
& Canada)" no longer describe them. Both provinces get their own entry.

`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`, and US Central time is
left to `US/Central` alone.

Author: gil-doesit

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [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

@@ -35,14 +35,15 @@
     # -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"),
     ("Canada/Saskatchewan", "Saskatchewan"),
     # -05
     ("America/Bogota", "Bogota"),
+    ("America/Winnipeg", "Winnipeg"),
     ("US/Eastern", "Eastern Time (US & Canada)"),
     ("US/East-Indiana", "Indiana (East)"),
     ("America/Lima", "Lima"),

timezones/test_timezones.py

@@ -1,3 +1,6 @@
+from datetime import datetime, timedelta
+from zoneinfo import ZoneInfo
+
 import pytest
 
 from . import _defs, tz_rendering, tz_utils, zones
@@ -89,3 +92,64 @@ def test_get_timezones_lists_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 = ZoneInfo(central_america_zone_names[0])
+    assert central_america_zone.utcoffset(december_2026) == timedelta(hours=-6)