What and why:
Three time zone changes affect Windows devices in Alberta, British Columbia, and Morocco, with Windows releasing fixes across September and October 2026. Alberta and affected Northwest Territories locations are permanently moving to UTC-6 on November 1, 2026. Most of British Columbia is permanently moving to UTC-7 on the same date. Morocco turned its clocks back one hour to UTC+0 on September 20, 2026. Microsoft recommends temporary workarounds for devices that can't be updated in time. For the workaround steps and full guidance for each region, visit the Daylight Saving Time & Time Zone Blog.
Rollout schedule:
- September 2026 – The Morocco change was included with the September 2026 Windows security update for all supported platforms. The Alberta and British Columbia time zones were included with the September 2026 Windows non-security preview update for Windows 11, versions 26H2, 26H1, 25H2, and 24H2.
- October 2026 – The Alberta and British Columbia time zones will be included with the October 2026 Windows security update for all remaining supported versions of Windows, including Windows Server.
- November 1, 2026 – The Alberta and British Columbia transitions take effect.
Impact on your organization:
In Morocco, devices will show an incorrect time until the update is installed. In Alberta and British Columbia, existing time zones remain correct until November 1, 2026; after that date, devices will show an incorrect time until the update is installed. For those two regions, the update adds a new time zone, (UTC-06:00) Mountain Time (Alberta) and (UTC-07:00) Pacific Time (British Columbia). Devices that set their time zone automatically will select the new time zone on their own; on other devices, users must select it manually.
Action required/recommendations:
Install the update on affected devices in Morocco now, and on devices in Alberta and British Columbia before November 1, 2026. If you can't install it in time, read and follow the interim guidance for each affected region, listed in Additional information.
Compliance considerations:
No compliance considerations are identified. Review as appropriate for your organization.
Additional information: