The updated software on myiPhone eliminated my calendar
Apple update my software on my phone this week and the next day appointments on my calendar were eliminated.
However, the calendar dates on my MacBook Air are still on.
iPhone XR, iOS 14
Question marked as
Find out which account is set to host your calendar on the mac, (System preferences, Internet accounts)
then in phone Settings, Calendar, Accounts, make sure the same account has calendar switched on