N.J. Stat. Ann. § 18A:39-5

At the time and place fixed in such advertisement for the submission of proposals the board of education, or any committee thereof authorized so to do, or any officer or employee of such board designated therefor, shall receive such proposals and immediately proceed to unseal the same and publicly announce the contents in the presence of the parties bidding or their agents, if such parties choose to be then and there present. Such board shall have the right to reject any and all bids. No proposals shall be opened previous to the hour designated in the advertisement and none shall be received thereafter.