Apple Calendar events one hour late from Alberta time zone.

Alberta Permanent Time Zone Change (Nov 1, 2026) Causing Recurring Calendar Events to Display One Hour Late on Apple Devices

We're seeing what appears to be a widespread issue affecting recurring calendar events on Apple devices following Alberta's move to a permanent UTC-6 time zone effective November 1, 2026.

What we're seeing

We have been able to consistently reproduce the issue in our environment.

• Recurring meetings that were created before the time zone change display correctly in Outlook on the Web (OWA) and Outlook for Windows.
• The same meetings display one hour later than expected on some iPhones, iPads, and Macs after November 1, 2026.
• The issue affects Apple's native Calendar app and, in some cases, the Outlook mobile app on iOS as well.
• Non-Apple platforms appear to show the correct meeting times.

Example

A recurring meeting scheduled for 8:00 AM daily continues to display as 8:00 AM in:

• Outlook on the Web (OWA)
• Outlook for Windows

However, after November 1, the same meeting appears as 9:00 AM on affected Apple devices.

Troubleshooting already performed

We've tested the common recommendations, including:

• Updating devices to the latest available OS versions
• Verifying automatic date and time settings
• Verifying location services and time zone settings
• Recreating calendar profiles/accounts
• Comparing behavior across multiple Apple devices

The issue persists.

Suspected cause

Based on our testing, it appears Apple devices may not yet be fully recognizing Alberta's new permanent time zone rules after November 1, 2026.

Because Outlook on Windows and Outlook on the Web display the correct time, it does not appear that the calendar data itself is incorrect. Instead, the issue seems to be related to how certain Apple devices or applications are interpreting Alberta's time zone information when calculating future occurrences of recurring events.

Questions for the community

1. Has anyone else in Alberta reproduced this issue?
2. Are you seeing it in Apple Calendar, Outlook for iOS, or both?
3. Are there any confirmed workarounds besides viewing calendars in OWA or Outlook for Windows?
4. Has Apple acknowledged any pending update to address Alberta's permanent UTC-6 time zone change?

Any feedback would be appreciated. We're trying to determine whether this is an isolated issue or something that may affect a larger number of Alberta users as November approaches.

Thanks!