Pay Periods are generated in Humanforce so it is aware of the pay cycles you have for payroll. The system supports any number of pay periods which can then be allocated to the pay company. A pay company can only have one current pay period, so where you have multiple pay periods, we would create separate pay companies in TimeTarget to support running separate pays for each pay period.
The pay period defines the cycle (e.g. Weekly, Fortnightly) as well as the start day (e.g. Monday).