Commencing with January 1st of the tax year, each three-month period constitutes a quarterly period, at which on or before the last day of the month following the end of such quarterly period the license fee or tax for the quarterly period is due. A monthly installment is permissible with the approval of the city clerk-treasurer; provided, that the installments are likewise due on or before the last day of the succeeding month and further that the monthly installments may not be converted to quarterly period installments except upon January 1st of the tax year. (Ord. 810, § 2, 1983.)