Abstract: A time accounting system for accounting parking subject to charge periods which includes a card having an electronic memory in which each memory location can be individually and irreversibly written in order to represent a time unit credit allocated to the holder of the card. The system also includes a portable case in which the card can be inserted and which has an internal clock circuit and a coupling circuit, as well as a writing circuit. The case is designed with means for temporary storage of a time unit credit which is activable if the time credit remaining in the inserted card is less than the parking time of the holder.