How to retrieve the mobile phone calendar

Check the phone settings and restore the backup.

1. Check the settings of the mobile phone: in the settings menu of the mobile phone, find the options of calendar or account and synchronization, and make sure that the calendar synchronization and backup functions are enabled.

2. Restore the backup: You can restore the calendar data from the backup. For iPhone users, you can back up and restore through iTunes or iCloud. For Android users, you can use Google account to back up and restore data through Google account.