Ohio Rev. Code § 5.30: Saturday afternoon is legal holiday.

Every Saturday afternoon is a legal holiday, beginning at twelve noon and ending at twelve midnight. No section of the Revised Code and no decision of any court shall affect the validity of any check, bill of exchange, order, promissory note, due bill, mortgage, or other writing obligatory made, signed, negotiated, transferred, assigned, or paid by any person, corporation, or bank upon said holiday, or any other transaction had thereon.