Microsoft 365 Alert – Service Degradation – Exchange Online – Users’ scheduled meetings may appear one hour ahead in Exchange Online – RESOLVED
21/03/2023 09:10:00 AM (GMT)
NHSmail Reference : INC34897307
Microsoft Reference : EX528773
Issue Status : RESOLVED
Issue Description : Users’ scheduled meetings may appear one hour ahead in Exchange Online.
More Information : This could affect any tenant scheduling a meeting with users within Mexico time zones.
For example, a meeting that is scheduled for 3:00 PM UTC by users but it shows up as 4:00 PM UTC within the invitee’s calendar.
Final Update : 03/04/2023 09:54:00 AM – Microsoft have confirmed that the deployment of the fix has now completed, and they have verified after monitoring the service that the fix has successfully resolved the problem.
Scope of impact : Any users’ meetings may appear to be scheduled for one hour ahead of its intended time if scheduling a meeting with users within Mexico time zones.
Root cause : The service infrastructure responsible for managing users” time zone data is missing a configuration required for time zone calculation for Daylight Savings in Mexico, resulting in impact.
Next steps : Microsoft are reviewing the change management processes related to Daylight Saving updates to determine how to avoid impact for future changes and reduce the amount of time needed to apply necessary updates to users.