Such declaration of estimated tax to be paid to the City shall be accompanied by a payment of at least 1/4 of the estimated annual tax and at least a similar amount shall be paid on or before the last day of the sixth, ninth and thirteenth months after the beginning of the taxable year. Provided, however, that in case an amended declaration has been filed, the unpaid balance shown due thereon shall be paid in equal installments on or before the remaining payment dates.
(1969 Code 92.25)