"Parking meter" means any mechanical device or meter placed or erected adjacent to a parking meter space, for the purpose of regulating or controlling the period of time of occupancy of such parking meter space by any vehicle. Each parking meter installed shall indicate by proper legend the legal parking time and when operated shall at all times indicate the balance of legal parking time, and at the expiration of such period shall indicate illegal or overtime parking. Each meter shall bear a legend indicating the days and hours when the requirement to deposit coins therein shall apply, the value of the coins to be deposited, and the limited period of time for which parking is lawfully permitted in the parking meter space in which such meter is located.