Ohio Rev. Code § 749.13: Bids to be sealed and indorsed.

Each bid for work and materials for the erection of a hospital building shall be enclosed in a sealed envelope and deposited with the clerk of the board of hospital commissioners, and such envelopes shall have indorsed thereon the nature of the bid. All bids shall be opened at the time, date, and place specified in the notice to bidders or specifications. The time, date, and place of bid openings may be extended to a later date by the board of hospital commissioners, provided that written or oral notice of the change shall be given to all persons who have received or requested specifications no later than ninety-six hours prior to the original time and date fixed for the opening.