How to find and remove duplicate calendar entries (Mac OS, Yosemite) I'm using the Calendar application on Mac OS X 10.10.1 "Yosemite". The calendar is laden with many years of history, and I've just imported some data from a phone as well. It turns out that some of the phone entries were new, but some were duplicates of entries already in Calendar.

Note that "duplicate" has some complicated cases. For instance, there are weekly repeating events where the phone's data correcting deleted some instances of the meeting (we didn't meet over the New Year holiday), while the original Calendar data incorrectly shows those instances occurring. Such pairs are "duplicate", even though they aren't identical.

How can I automate the process of identifying which calendar entries are duplicates, choose which one to keep, and delete the other? Is there AppleScript magic or something?
It can't be done since Apple doesn't think that's something anyone would ever need to do.

Maybe it's time for Apple to invest a few cycles in updating iCal, Contacts and Email - they haven't been updated in a decade.