(a) Wages other than fringe benefits and wage supplements. Every employer shall pay all wages, other than fringe benefits and wage supplements, due to his employes on regular paydays designated in advance by the employer. Overtime wages may be considered as wages earned and payable in the next succeeding pay period. All wages, other than fringe benefits and wage supplements, earned in any pay period shall be due and payable within the number of days after the expiration of said pay period as provided