(a) The governing authorities of the several counties, municipal corporations, and other political subdivisions of this state are authorized to designate and set apart a portion of the compensation, whether payable on a salary or fee basis, to sheriffs, deputy sheriffs, patrolmen, policemen, and other law enforcement officers, as a subsistence allowance, which allowance shall not exceed $5.00 for each day actually spent by such sheriff or other law enforcement officer in the performance of his duties.

(b) Nothing in this Code section shall affect any pension system which was being operated by any county, municipal corporation, or political subdivision of this state on March 9, 1956, nor shall this Code section affect any rights of any person under any pension system which was being operated by any county, municipal corporation, or political subdivision on March 9, 1956.