Yesterday my Apple Watch started showing duplicate events in the Calendar app and on the watch face (when events overlap, an exclamation point icon appears before the next event on the face). I’m not sure what spurred the issue, but for some reason this week my iPhone stopped updating iCloud information until I re-entered my password in the iCloud settings.
The duplicates didn’t appear in the Calendar app on the iPhone, nor in my iOS calendar of choice, Fantastical. In fact, Fantastical on the watch also didn’t show duplicate events.
This looks like a bug somewhere in iOS or watchOS related to having an alternate calendar app installed on the iPhone. In theory, all calendars use the same underlying database, but that’s not happening in this case. Fortunately, it’s easy to fix:
- On the iPhone, open the Calendars app (Apple’s built-in one, not a third-party one).
- Tap Calendars at the bottom of the screen.
- Tap the “All iCloud” button to toggle all calendars’ visibility from on to off.
- Tap Done.
The duplicates are hidden on the watch. Your events still appear in the third-party calendar you use.
Although I prefer the Fantastical app on the watch, I usually find myself in the built-in Calendar app because I tap the notification on the watch face for quick reference. watchOS 2, available in a few months, supports custom watch face complications, so hopefully I’ll be able to launch whichever app I want then.
Want to know more about the Apple Watch and how best to take advantage of it? Buy my book! Apple Watch: A Take Control Crash Course, is just $10 and an immediate download.
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Jeff Carlson | Never Enough Coffee Creations 
I face the same problem sometimes with my Apple watch and I couldn’t find a proper solution till date. Glad I finally got it. Thanks a lot
This solved my problem. Thank you!