218.73  Timely payment.--The time at which payment for a purchase by a local governmental entity, except for the purchase of construction services, is due must be calculated from:

(1)  The date on which a proper invoice is received by the chief disbursement officer of the local governmental entity after approval by the governing body, if required; or

(2)  If a proper invoice is not received by the local governmental entity, the date:

(a)  On which delivery of personal property is accepted by the local governmental entity;

(b)  On which services are completed;

(c)  On which the rental period begins; or

(d)  On which the local governmental entity and vendor agree in a contract that provides dates relative to payment periods;

whichever date is latest.