Chartered Accountant
39039 Points
Joined September 2008
The earliest of the 3 events for normal transactions: receipt of payment, billing or completion of service. As no billing or reciept and as per contract it is September. Not required to be paid earlier.
It could be said tobe constinuos supply under which also the contract specifying that payment to be made in september would apply unles spayment recived earlier or billed earlier.