Ohio Revised Code Title XXXIII. Education Libraries § 3311.85

(A) The board of education of each municipal school district annually shall approve a calendar or calendars establishing a school year that complies with the minimum school year prescribed by section 3313.48 of the Revised Code. The board has final authority to establish a school calendar, including the starting and ending times for the school day, for one or more of the district's school buildings that provides for additional student days or hours beyond the minimum prescribed by that section. A school's calendar may prescribe year-round instruction or an extended school day.

(B) Notwithstanding any provision to the contrary in Chapter 4117. of the Revised Code, the requirements and authorizations of this section prevail over any conflicting provisions of a collective bargaining agreement entered into on or after the effective date of this section. However, the district board and teachers' labor organization shall negotiate regarding any additional compensation for an extended school year or school day, consistent with section 3311.78 of the Revised Code.