Update to MC1510951: Canada 2026 time zone changes — Microsoft 365 impact and required admin actions

This post updates MC1510951 ((Updated) Windows updates are available for 2026 time zone changes in Canada, posted October 16, 2026).

On November 1, 2026, affected locations in British Columbia, Alberta, and Manitoba will not move clocks back and will remain on UTC-07:00, UTC-06:00, and UTC-05:00 respectively. Affected locations in the Northwest Territories (including Yellowknife and Inuvik) align with the Alberta change, and Northwestern Ontario aligns with the Manitoba change.

Windows and Microsoft 365 services depend on updated time zone definitions for correct scheduling and display behavior.

How this affects your organization

Confirmed impact

1. Outlook and Exchange Online (calendar): Users must move to the new time zone. Existing events do not migrate automatically. Recurring meetings require additional review.
2. Microsoft Teams Rooms on Windows: Some devices may display time one hour behind Windows until Edge/WebView2 is updated.

Potential impact (under validation)

1. Microsoft Teams (desktop, web, mobile) and other Teams devices
2. Outlook for iOS, Android, and Mac
3. Microsoft Bookings
4. Shifts
5. SharePoint Online
6. OneDrive

What you need to do

1. Ensure Windows devices in affected regions have the latest Windows updates (including October 2026 updates).
2. Ask users in affected regions to select the new time zone in Outlook and review meetings scheduled after November 1, especially recurring series.
3. Plan to run the Exchange Online PowerShell remediation cmdlet for non-recurring meetings once released (target: October 28, 2026).
4. Update Microsoft Edge and WebView2 on Teams Rooms on Windows and confirm room time display matches Windows.
5. Keep Teams, Outlook (including iOS/Android/Mac), and other Microsoft 365 apps current.
6. Test key scenarios before November 1: recurring meetings, free/busy, Bookings appointments, Shifts schedules, and SharePoint regional settings.
7. If issues occur, open a support case in the Microsoft 365 admin center and include #Canada Time-Zone in the title.

Additional information

• Outlook Time Zone Changes for British Columbia, Alberta, and Manitoba (Microsoft Support)
• Interim guidance for British Columbia time zone changes 2026 (DST Blog)
• Interim guidance for Alberta time zone changes 2026 (DST Blog)
• Manitoba 2026 time zone update available now (Daylight Saving Time and Time Zone Blog)

We will continue updating this post as product teams confirm impact, publish mitigations, and release additional guidance.