One possible explanation for the duplicates is if you had calendars and events on the MacBook Pro and then synced to iCloud, the IMac calendars were added to the ones already on the MacBook Pro.
Log onto iCloud.com and see if you have multiple calendars there.
Quit Calendar. Try going to System Preferences/iCloud and unchecking the box to sync calendars. Then open Calendar and see if you still have duplicates. If not, and you still want to sync, then you may be better off deleting the calendars on the MacBook Pro and just allow the iCloud calendars to be your only source of calendars.
Once you have stopped the sync, check iCloud.com to see if you have duplicates.
I stopped al sycing and still have lots of duplicates. My next question is, can I go to the Library and find the calendar files and trash the duplicates? Is each calendar a separate file? Should I have over 30 xxx.calendar files?
What exactly should I have in the Library for the calendar system?
Thanks for any ideas.
I think this will allow you to get back to where you were.
Before you do the restore from Time Machine portion, you might try turning on iCloud sync again to see what you get. I do not have any "On My Mac" calendars anymore because they were causing duplicates when I synced with iCloud.
I went to iCloud, the website, and counter 81 calendars! There are only about a dozen actuals names (Birthdays, Misc). Somehow I have created a complete mess!
If I try to turn off the syn in either achine, I get a message that says if Iturn off the Sync, I wikklose all the info on my machine. Is that correct? Can I not delete calendars from the iCloud website? Somehow!