Most of the time, the duplicates will only appear in one or two calendars, and only on one device. Some of these duplicates come from those Apple special calendars that you can subscribe to - U.S. In my case, I use both iCloud-synced calendars and Google calendars. There’s a way to fix that problem once and for all…īefore we delve into the fix, let’s talk about some of the situations that seem to cause this issue. Sometimes an event will be duplicated over and over, often filling a day on the calendar with copies of the same exact event. There’s an odd little problem with the macOS Calendar app that I’ve run into a number of times, both personally and during my years as a Mac consultant.