The reason for creating a Payroll Calendar is to define the work days for Payroll processing purpose.
Step 1,2 & 3 : Go to Payroll -> General Setting -> Payroll Calendar Group Settings,
Step 4: click 'Create' button.
Step 5: Define the name of the calendar and also work hour.
Step 6: Tick any day that you want to exclude from as work day for payroll processing.
Step 7: Alternatively, you can choose to define number of days per month. For example, 26 days for every month. To do so, tick the 'User Defined' radio box.
Step 8: Enter number of days in each month, then click 'Save' button.