Unless the board of supervisors of a county provides by ordinance for more frequent pay periods, the salaries of the officers named in this title and all county deputies, clerks, and employees who are entitled to salaries shall be paid monthly out of the county treasury. The sworn statement and copy of the treasurer’s receipt for all fees and other money required to be paid into the county treasury required by Section 28005 shall be required to be filed in such event only prior to payment of the final installment of the salary of any officer for any month.