Sportéa offers a club a maintenance subscription for its equipment, renewed automatically each month. Each party may end it at any time, without penalty, with effect at the end of the current month. It is established (legal analysis, case datum) that the enforceable rights and obligations cover only the current month. The club has been a subscriber for three years and Sportéa expects it to remain one. Over what period does Sportéa apply IFRS 15 to this contract?