All license fees, unless otherwise provided by ordinance, shall become payable on July 1 in each year, or on the commencing of any business or occupation upon which the license fee is imposed by ordinance.  In the former case the license fee shall be reckoned for 1 entire year; and in the latter case it shall be reckoned proportionately from the first day of the month in which the liability to the license commenced, until July 1 next following.  For all purposes connected with the issue and expiration of any class or kind of license required by any ordinance of the city, it is hereby provided that the municipal year of the city shall begin on the first day of July in each year.
(1983 Code, § 13-4)