Each parking meter required by this article shall plainly indicate the hours of the day during which its use shall be required and the parking space to which it is appurtenant. When any vehicle is parked during such hours in a space provided for above, the driver shall, immediately upon entering such space, deposit a coin or coins of the United States in the adjacent parking meter. Each meter shall indicate the total length of time the adjacent space may be used by each operator and the length of time for which the deposit of coin will entitle the operator to use the space. After coins are deposited in a parking meter as required above, a mechanical device on the meter shall continuously indicate the remaining length of time during which the adjacent space may be used. When such time has fully expired, a mechanical device on the meter shall plainly so indicate. (1978 L.M.C., ch. 7, § 2.)