Android to Google calendar sync problems The option to sync calendars is missing from the list for my 2 Google accounts, following some issues with syncing after which I deleted calendar data and calendar storage data.

I have tried reloading the accounts and all the other options come back - except the Calendar sync!!

Please help..
I am assuming you are on a rooted device.

Use your preferred file explorer to browse to : /system/app

There should be two apk files. One the calendar app (calendar.apk) and the other calendarprovider.apk. The second apk provides proper synchronization between the google account and the actual calendar application which is probably missing or not working. 

You should be able to find a replacement apk for your specific device and rom on XDA.