New Outlook for Mac and Outlook for iOS display Alberta calendar events one hour late after November 1, 2026

The behavior matches a known Outlook calendar display issue related to daylight saving time transitions across multiple time zones.

Microsoft documents a scenario where Outlook can show incorrect time differences when DST starts or ends, especially when time zones change on different dates or one zone stops observing DST. In that condition, calendar events can appear at the wrong time in the calendar view even though the underlying event time is correct.

For Alberta after November 1, 2026, Microsoft’s published guidance is:

1. Change the Outlook calendar time zone to (UTC-06:00) Mountain Time (Alberta).
   • In new Outlook, Outlook on the web, or Outlook.com: Calendar settings > Calendar > View > Time zones > Display my calendar in time zone.
   • Select (UTC-06:00) Mountain Time (Alberta), add a label if needed, and Save.
2. Update affected upcoming events and meetings to the new Alberta time zone.
   • Open the event.
   • For meetings with attendees, only the organizer can make the change.
   • For recurring meetings, select Edit Series.
   • Click the time block, then click the globe time zone icon.
   • Change the event time zone to the new Alberta time zone.
   • Save or Send the update.
3. For recurring series, expect exceptions to be reset.
   • Any moved or modified instances in the series can be cleared when the series time zone is changed, so those exceptions must be recreated afterward.

What is supported by the published guidance:

• Alberta has a new Outlook-supported time zone: (UTC-06:00) Mountain Time (Alberta).
• Users affected by the Alberta change must adopt the new time zone in their calendar and migrate upcoming events.
• Outlook on the web is included in the supported update path for changing the calendar time zone and updating future meetings.

What is not confirmed in the published material:

• There is no explicit statement confirming a specific New Outlook for Mac or Outlook for iOS client bug for Alberta rendering one hour late.
• There is no published fix date or client-specific workaround for Mac or iOS beyond adopting the new Alberta time zone and updating affected future events.

If Outlook on the web already shows the correct time while New Outlook for Mac and Outlook for iOS show the event one hour later, the documented supported workaround is to ensure the mailbox/calendar and the affected events are using (UTC-06:00) Mountain Time (Alberta) and then resend or save updated events where needed.

References:

• Outlook Time Zone Changes for Alberta and British Columbia
• Multiple time zones show an incorrect time difference when DST starts and ends
• Set the time zone for a meeting or appointment in Outlook for Mac