The invitation to bid gives the time and place. A bid that arrives after that time is normally not accepted.
At a public opening, the owner reads each bidder's base bid and alternates. The results are apparent until the owner reviews each bid.
Subs do not attend most openings, but the time rules their day. General contractors need sub numbers well before the opening.
Send your scope early and your price in time for the GC to use it. A late number often goes unused.