[valentinbonneaud]

Alberta, Manitoba and British Columbia moved to permanent time on 2026-11-01. Outlook/Exchange now sends invites and calendar exports with new Microsoft time zone names that TimeZoneUtil can't resolve:

• TimeZoneUtil::getTimeZone($tzid, $vcalendar, failIfUncertain: true) throws We were unable to determine the correct PHP timezone for tzid: Alberta Standard Time, so callers that parse DTSTART drop the event.
• Without $failIfUncertain, it silently falls back to the PHP default time zone, so the event lands at the wrong time.

Change

Adds to lib/timezonedata/extrazones.php:

Microsoft name	IANA zone
Alberta Standard Time	America/Edmonton
Mountain Time (Alberta)	America/Edmonton
Manitoba Standard Time	America/Winnipeg
Pacific Time (British Columbia)	America/Vancouver
British Columbia Standard Time	America/Vancouver

The other forms Outlook produces already resolve once the base name is mapped:

• Alberta Standard Time 1 (numbered variants in Outlook exports), through FindFromMzVersionTimezone
• (UTC-06:00) Mountain Time (Alberta) (offset-prefixed display names), through the existing patterns in FindFromTimezoneMap

Tests

• TimeZoneUtilTest::testCanadaPermanentTimeZones covers 9 forms: each name, the numbered … 1 variants and the (UTC±hh:mm) … prefixed variants. All 9 fail without the new entries.
• vendor/bin/phpunit -c tests/phpunit.xml (3,301 tests), phpstan analyse lib tests and php-cs-fixer fix --dry-run are green.