Each parking meter shall be set to display, after the operational procedure has been completed, a sign or signal indicating legal parking for that period of time conforming to the limit of parking time or portion thereof for which payment has been made for the zone in which said parking meter is installed, and shall continue to operate from the time of the completion of the operational procedure until the expiration of the time fixed as the parking limit or a portion thereof for the parking space for which said meter is placed. Each parking meter shall also be arranged so that upon the expiration of said legal parking time it will indicate by a mechanical operation and by proper signal that the lawful parking period has expired. (Ord. 3138 § 3, 2009; Ord. 2670 § 1, 1996; Ord. 973 § 1, 1966; prior code § 19.17.2(B)).