Wages must be paid on established paydays. A payment interval may be daily, weekly, biweekly, semimonthly, or monthly. The maximum interval between paydays is 1 month. If an employer pays wages on a basis of a pay period that is less than 1 month, the regular payday shall be no later than 10 calendar days after the end of the pay period. If an employer pays wages on a basis of a monthly pay period, the employer may establish a regular system under which wages for work performed in the last 7 days of the month may be paid with the wages for the next pay period. Employers may establish a separate payday for overtime wages if such wages cannot be determined until after the regular payday (WA Admin. Code Sec. 296-126-023).