Ohio Rev. Code § 307.17
In the absence from an agreement entered into under sections 307.14 to 307.19, inclusive, of the Revised Code, of a specification of its own duration, such agreement shall continue in effect until it is rescinded. Every such agreement, whether for a definite term or of indefinite duration, may provide for its own rescission and the method of rescission. In the absence of any such provision, such agreement may, at any time, be rescinded by the agreement of both parties, and an agreement of indefinite duration may at any time be rescinded by resolution of either party to the agreement, effective at the end of the fiscal year, not sooner than six months after such rescinding resolution has been certified and delivered to the clerk or secretary of the other party.
R.C. §307.17