Ohio Revised Code Title XXXIII. Education Libraries § 3319.0811

(A) Except as provided in division (B) of this section, if the board of education of a school district offers to students of compulsory school age courses for high school credit that are taught at times outside the district's normal school day, the board shall enter into supplemental contracts under section 3319.08 of the Revised Code with the teachers assigned to teach those courses and shall not include such assignment of duties within the teachers' regular employment contracts under that section.

(B) A supplemental contract shall not be required under this section if a teacher voluntarily agrees to a regularly occurring schedule that begins or ends outside the normal school day, so long as the teacher is not assigned more total daily hours than a teacher assigned to the district's normal school day and is otherwise in compliance with applicable requirements of the district's collective bargaining agreement.