There is hereby created by an advance from the appropriate fund a payroll revolving fund for the city, which fund shall be of an amount approximately equal to the gross payroll for two (2) weeks as from time to time determined, and which shall be deposited in a national bank in the city, and out of which fund all employees of the city shall be paid every two (2) weeks. All other payroll transactions on behalf of employees shall be paid as required by checks drawn on such fund by the director of finance administration. (1962 Code § 2-6.202)