Ohio Revised Code Title XXXV. Elections § 3501.32

(A) Except as otherwise provided in division (B) of this section, on the day of the election the polls shall be opened by proclamation by the voting location manager, or in the manager's absence by a voting location manager chosen by the precinct election officials, at six-thirty a.m. and shall be closed by proclamation at seven-thirty p.m. unless there are voters waiting in line to cast their ballots, in which case the polls shall be kept open until such waiting voters have voted.

(B) On the day of the election, any polling place located on an island not connected to the mainland by a highway or a bridge may close earlier than seven-thirty p.m. if all registered voters in the precinct have voted. When a polling place closes under division (B) of this section the voting location manager shall immediately notify the board of elections of the closing.