Ohio Rev. Code § 3313.63: School holidays specified.

Boards of education may dismiss the schools under their control on the first day of January, the third Monday in January, the third Monday in February, the day designated in the "Act of June 28, 1968," 82 Stat. 250, 5 U.S.C. 6103, as amended, for the commemoration of Memorial day, the nineteenth day of June, the fourth day of July, the first Monday in September, the second Monday in October, the eleventh day of November, or the succeeding Monday when that day falls on a Sunday, the fourth Thursday in November, and the twenty-fifth day of December, on any day set apart by proclamation of the president of the United States or the governor of this state as a day of fast, thanksgiving, or mourning, or on the days approved by the board for teachers' attendance at an educational meeting.