Scenario:
Customer has four departments in his company, each department is entitle to get a flex day once in four weeks on rotational bases. Instead of employees booking or adding time off, the administrator wants it to be auto populated.

Resolution:
The above scenario can be addressed by creating four holiday calendars with similar holidays and associate them with the four groups. Also, update the calendars with the flex days based on the flex days given to the departments.
 
Example:
Department A : Holiday A
Department B : Holiday B
Department C : Holiday C
Department D : Holiday D
 
Update all the calendars with similar holidays and then update "Holiday A" with the flex days given to "Department A" and update the remaining holiday calendar respectively. Associate the time off type "Holiday" for auto population and then enable the Holiday time off type for all the users.
 
Refer the Related Items in this knowledge base below to know more about how to enable or disable the Auto-Populate holiday hours feature on users' timesheet.
 
Note: The administrator must update the holiday calendars before the timesheets are generated.
 

Related Items:

How to enable or disable the Auto-Populate holiday hours feature on users’ timesheet?