Parking meters installed in the parking meter zones shall be placed upon the curb or sidewalk, and immediately adjacent to the individual parking spaces described in § 72.017. Each parking meter shall be placed or set so as to show that the parking space adjacent to that meter is or is not legally occupied. Each parking meter installed shall indicate by a proper legend the legal parking time established by the borough and when the adjacent space is occupied by a vehicle, the parking meter shall indicate on and by its dial and pointer the duration of the period of legal parking and, on the expiration of that period, shall indicate illegal parking or over-parking.