The last time it closed, in 2007, the contractor for the job was the company that fixed the Northridge damage in weeks and replaced a bridge at the McArthur Maze (at the Oakland end of the bridge)that was destroyed by a tanker fire in 3 weeks! That time it opened up 12 hours ahead of schedule.
They also have to watch the winds. If they get too high, they have to suspend work. They say that they expect the winds to be low (<10 mph) this weekend.
It's amazing how they thought all this out.
The new bridge will be a little higher. When the new cranes for the Port of Oakland come in from China (some say George Lucas got the idea for the Imperial Walkers from them). the ship has to sit out in the bay near Alcatraz until low tide, then scoot under the existing bridge. A guy stands on the top of the crane to be sure there is clearance. He can touch the steel on the bridge!