Recovering Deleted Items in Outlook
Problem: Items on a shared calendar (either an individual or office calendar) were deleted and need to be recovered
Solution 1: The individual who deleted the items will have them in their "Deleted Items" folder. Have that individual drag the deleted items from their Deleted Items folder back into the shared calendar.
Solution 2: Contact the Helpdesk with as much information on the deleted appointments and who deleted them. Try to include: date, time, title of each appointment if possible.