After upgrading to iOS 7, users found that their Google Calendars aren't showing up on the stock Calendar app. At first, it was thought to be a server-side issue but it turns out that you will have to find a fix for the sync issue yourself.
Fortunately, the fix isn't all that big. After you upgrade your iDevice to iOS 7.x, you just have to make sure you re-add the Gmail account. But you must also make sure that you get a few things right. Here's all about syncing Google Calendars to iOS 7 (on iPhone and iPad) and fixing issues that you might face during the process.
HOW TO SYNC GOOGLE CALENDARS
- Open the Settings app
- Tap on Mail, Contact & Calendars
- If you have added your Gmail account to iOS already, tap on it under Accounts
- Turn ON the switch for Calendar.
- If you have not added your Gmail account, under Accounts, tap on Add Account…
- Select Google.
- Now, enter the details (username, password and a name). This is important: if you use a 2-step verification, you must enter an application-specific password instead of the usual password.
- Next up, once your account has been verified by the server, you will be given the option to turn on sync for Mail, Calendars and Notes. Make sure you turn on the switch for Calendars here.
- That's about it.
That sounded easy. It is but if you did all of that on iOS 6 and then upgraded to iOS 7, you probably had all Google Calendars removed from your app. I haven't been able to figure out the “why” of it but the fix for this problem is pretty simple and straight-forward. Here's how it goes:
- Go to Settings → Mail, Contact & Calendar
- Under Accounts, tap on the Gmail account.
- Right at the bottom, you have Delete Account. Tap that.
- Delete the account completely.
- Now, follow the first batch of steps to re-add your Gmail account.
If you used Exchange or CalDAV accounts to add calendars, things have changed and so errors are quite common. In fact, most of the sync issues crop from accounts where Exchange or CalDAV was used to add the Calendar (or account).
One more thing that you must do is go to Google Mobile Sync (from your iPhone or iPad) and then from here, select all calendars that you want synced with your Calendar app. Basically, you have to tell Google what calendars you want to open up for iOS. Then, proceed with the steps above to fix all sync issues.