I saw your post yesterday and waited for others to answer. I think it only takes a few hours.
If you have it, a push in queen cage on empty drawn comb left in place for the same amount time may help with the pheromone as she fill the cells. I've found that if they get into the queen cell building mode, they won't accept the new queen.
If that happens, I do my best to get out of the way, wait and watch. It's worked out, so far.