User impact: Users may have seen some meetings scheduled in Mexico time zones were displaying with the incorrect time.

More info: Users may also have experienced the problem in the Microsoft Teams calendar as it leverages the Exchange Online service.

Some users saw meetings scheduled an hour ahead of the intended time within Outlook on the web, Outlook mobile, the Outlook desktop client, and all Microsoft Teams connection methods when accessing the calendar.

For an immediate fix for reoccurring meetings created on or before April 1, 2023, that also had an instance of this meeting modified after this date, meeting organizers could have made any small update, such as editing the subject or body, and save the change.

Final status: We’ve completed the remainder of our fix deployment and have confirmed with previously affected users that impact was successfully resolved.

Scope of impact: This issue could have affected any attendee with meetings scheduled by some users in the Mexico region.

Start time: Wednesday, April 5, 2023, at 8:55 PM UTC

End time: Thursday, June 22, 2023, at 10:00 PM UTC

Root cause: A code conflict during meeting creation and updating was causing time zone data to be handled incorrectly for some meetings.

Next steps:
– We’re reviewing the code responsible for meeting creation and update to determine methods to prevent similar impact from occurring during the next time change.

This is the final update for the event.