Cal. Food & Agric. Code § 18695

If slaughtering or carcass preparation or processing of any meat, meat products, poultry, or poultry product is conducted in an establishment where state inspection is maintained, at hours considered overtime for state employees, or on legal holidays, the owner or operator of the establishment shall, by contract or agreement with the department, make arrangement to defray the additional cost for salaries and expenses for persons employed by the department to conduct the necessary inspection work during the overtime periods.