Montana Title 28. Contracts and Other Obligations § 28-1-1301. When delay or failure to perform or offer to perform excused

(1) when such performance or offer is prevented or delayed by the act of the creditor or by the operation of law, even though there may have been a stipulation that this shall not be an excuse;

(2) when it is prevented or delayed by an irresistible, superhuman cause or by the act of public enemies of this state or of the United States, unless the parties have expressly agreed to the contrary; or

(3) when the debtor is induced not to make it by any act of the creditor intended or naturally tending to have that effect, done at or before the time at which such performance or offer may be made, and not rescinded before that time.