There are two ways you can use the breatheHR calendar sync.
Means the HR user is in control of the calendar, this is generally used to import all holiday for the entire company into one main calendar or into a departmental calendar.
Allowing employees to manage their own calendars
Allows them to sync their own calendars with breatheHR.
To manage the calendar sync go to Settings > Absence settings > Calendar subscriptions.
If you would like to manage your calendar centrally click here for instructions
If you would like your employees to manage their own click here for instructions