Eliminating doubled iPhone calendar entries

I upgraded to iOS 5 last Thursday, and it went pretty smoothly. The only exception was that most of my calendar events showed up doubled on the iPhone. After a weekend of hoping it was a temporary iCloud glitch that would resolve itself, I decided on Monday I needed to do something to fix it. I came up with something that seemed to fix it, and since the problem hasn’t returned I figured it was time to write it up.

I have the iPhone, an iMac, and a MacBook Air synced to share my contacts, calendars, reminders, and bookmarks via iCloud. Contacts, reminders, and bookmarks have had no problems at all. My calendars looked fine in iCal on both the iMac and the MB Air and in the iCloud web app on icloud.com, but most of the events were doubled on the iPhone.

Was there a pattern to which events were doubled and which weren’t? Yes and no. On the yes side:

On the no side, repeated events I made myself—like birthdays, anniversaries, and holidays—were sometimes doubled and sometimes not. If there was a pattern to these, it was beyond me.

My first attempt to fix things was to delete one of the doubled events from my iPhone. When I did that, I got down to just one copy on the iPhone, but that event would be deleted entirely from the iMac, the Air, and iCloud. Similarly, if I deleted an item from the iMac, the Air, or iCloud, only one copy would be deleted from the iPhone. This was obviously not a solution, but it suggested that for some reason local copies of some events were “stuck” on my iPhone.

I went into Settings on the phone and turned off both calendar syncing and the subscriptions. Even though the subscriptions weren’t causing trouble, I wanted to start over with a completely empty calendar on the phone. After turning everything off, I went back to the Calendar app1 and scrolled around until I was convinced that everything was gone. Then I went back into Settings and turned the iCloud calendar syncing and the subscriptions back on.

Voila! Almost.

When I returned to the Calendar app, the syncing began and little dots started appearing in the Month view for every event. When I touched a day to see the events in it, none were doubled. Great. The only remaining problem was that when I went to List view (my preferred view) not a single event appeared. I switched back and forth between views to see if that would somehow force Calendar to reread its database and populate List view, but that didn’t work.

I tried shutting down Calendar and relaunching. That didn’t work, either.

Finally, I tried the one thing I hate to do: rebooting. I don’t hate it because it’s ineffective, I hate it because it’s so simple-minded and Windowsy, and I feel like a fool when I have to resort to it. As I’m sure you’ve guessed by now, rebooting did the trick; all the events appeared (just once) in each view.

I’m sure there’s a logical explanation for everything that happened—both good and bad—but I have no interest in tracking it down. My calendars are in sync, and that’s good enough for me.

  1. Normally I use Agenda, but I thought it would be better to use the Apple-supplied Calendar until I got this doubled event problem sorted out.