Migrate a calendar from Office 365 Outlook to PST

Contract ending, and my 365 calendar holds two years of project meeting history the client says I may keep for my records.

How do I get the calendar, just the calendar, out as a file before the account closes?

The export wizard handles a calendar only PST cleanly, with a date filter if you ever want a subset.

1

In desktop Outlook connected to the 365 account: File, Open and Export, Import/Export, Export to a file, Outlook Data File (.pst).

2

In the folder tree select Calendar under the 365 mailbox. Leave Include subfolders ticked if you created any sub calendars.

3

Click Filter if you want a date range only, otherwise skip it to take the full history including recurring series.

4

Save the PST somewhere personal, choose the duplicates option, Finish. Open it later on any Outlook via File, Open and Export, Open Outlook Data File and the calendar appears in the calendar view's folder list.

Two boundaries to know. Shared and delegated calendars belonging to other people do not export with your mailbox, only calendars you own travel. And meeting items in the PST become historical records: the attendee lists and notes are preserved but they detach from the live meetings, so no updates or cancellations flow after export, which for a keep for your records purpose is exactly the behaviour you want. An ICS export via Save Calendar is the alternative when the destination is something other than Outlook.

Exported the full two years to PST and confirmed it opens on my personal Outlook, recurring project meetings intact. Records kept, contract closed.