The first day on which notice of intent to deliver a commodity in fulfillment of an expiring futures contract can be given to the clearinghouse by a seller and assigned by the clearinghouse to a buyer.
If you must play, decide upon three things at the start: the rules of the game,
the stakes, and quitting time
Generally the last date on which a future and an option contract may be exercised. It is the date specified in the contracts.