A promise or order is "payable on demand" if: (1) it states that it is payable on demand or at sight or otherwise indicates that it is payable at the will of the holder; or (2) it does not state any time of payment.
Payable On Demand
Mont. Code Ann. § 30-3-108, under Short Title, Form, and Interpretation.
Mont. Code Ann. § 30-3-108