Hi noel BURKE,
I completely understand your concern. It can be quite frustrating when your calendar data is stuck locally and not syncing with your active account.
Based on my research and testing in a virtual environment, the solution depends on the type of items stored in your "On My Computer" folder:
1. For Appointments: If the items are simple Appointments (events created by you without other attendees), you can manually move them. The best way is to switch your Calendar View to "List" view, select the items, and drag and drop them into your active Outlook account calendar.
2. For Meetings (Events with attendees/organizers): My research indicates that Meetings should not be stored in the "On My Computer" folder, and moving them is generally not supported.
According to Microsoft: "If you move a meeting from one calendar to another, the action might trigger discrepancies between your instance of the meeting and the information that the meeting organizer or other attendees have. In such a scenario, you might miss important updates sent by the meeting organizer."
Because of this risk, this functionality isn't officially supported in Outlook for Mac.
Reference: Can't move meetings between calendars in Outlook for Mac
I hope this information is helpful to you.
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