All assessments shall be computed on those businesses in existence as of July 15 of each calendar year. All assessments will be due and payable in advance on August 1 of each year for the period commencing August 1 of each year and ending July 31 of the succeeding year, and will become delinquent if not pay by September 1 following the due date. Delinquent payment shall be subject to the same penalties for late payment as provided in Section 19-21 of this code with respect to annual business licenses. (Ord. No. 2281 (NCS), § 5.)