The auditor shall issue his warrant on the county treasury for such an amount for each claim as he finds to be a correct and legal county charge. He shall not issue his warrant for any claim that has not been on file in his office for at least three days. Notwithstanding the foregoing, the board may, upon recommendation of the county auditor, provide by ordinance that the three-day waiting period shall not apply to any claims or to specified classes of claims.