Sync Diary
This screen enables you to set-up Diary synchronisation.
To access this screen visit File → 3rd Party Configuration → Miscellaneous → Diary Synchronisation

This is also a configuration setting against each User via the User settings on their contact record.

https://www.youtube.com/watch?v=xOvK2HEupDc
To set-up Diary synchronisation click on the respective link below