N.D. Cent. Code § 1-03-04
All days other than those mentioned in sections 1-03-01, 1-03-02, and 1-03-02.1 are to be deemed business days for all purposes. However, any bank may remain closed on any one business day of each week, as it may from time to time elect. Any day upon which a bank is so closed shall be, with respect to such bank, a holiday and not a business day. Any act authorized, required, or permitted to be performed at or by or with respect to such bank on such day, may be performed on the next succeeding business day, and no liability or loss of rights shall result from such delay.
Notice of intention on the part of any bank to remain closed on a business day of the week shall be posted in a conspicuous place in the lobby of the bank at least ten days prior to the establishment of such practice and similar notice shall be given when a bank elects to change the day of the week on which it remains closed. Any state bank establishing the practice, as hereinbefore provided, of closing one day a week shall give ten days' notice in writing to the commissioner of financial institutions, in addition to posting the notice in the lobby. However, any bank may elect to remain closed on a business day of the week without any prior notice in the event of the following emergencies: any act of God, death of an officer, or a robbery.
N.D.C.C. § 1-03-04