Okla. Stat. tit. 25 § 82.2
The following additional days are designated as holidays:
Jefferson Day on the 13th day of April; Oklahoma Day on the 22nd day of April; Mother's Day on the second Sunday in May; Juneteenth National Freedom Day on the third Saturday in June; Indian Day on the first Saturday after the full moon in September; Cherokee Strip Day on the 16th day of September; Will Rogers Day on the 4th day of November; Citizenship Recognition Day on such date as may be fixed by the Governor; Oklahoma Historical Day on the 10th day of October; Senior Citizens' Week beginning with the first Sunday in the month of May; Senior Citizens' Day the Wednesday of Senior Citizens' Week; Grandparents' Week beginning with the second Sunday in September; Youth Day on the third Sunday in March each year; each day in which a state election is held throughout the State of Oklahoma; and such other days as may be designated by the President of the United States or the Governor of the State of Oklahoma. Notwithstanding the day designated for Veterans' Day by Section 82.1 of this title, any bank, savings and loan association or credit union may observe the fourth Monday in October as Veterans' Day. Any act authorized, required or permitted to be performed on any holiday as designated in this section may and shall be performed on said day the same as on any business day; provided any state, national or federal reserve bank, building and loan association, credit union, state, federal, county or municipal office may close on any day designated in this section as a holiday, and, upon such bank, building and loan association, credit union, or public office being closed on such day, any act authorized, required or permitted to be performed at or by such bank, building and loan association, credit union, public office or public official may be performed on the next succeeding business day and no liability or loss of rights of any kind shall result from such delay.
Okla. Stat. tit. 25, § 82.2