Fortunately, our 10:30 assigned arrival time was pretty spot-on. They brought us into the little room for surgery preparations. Doctors and nurses came to see us when they were supposed to.
The Boy received Tylenol and a "happy juice" kind of drug, to relax him and make him a bit floppy.
The only little hitch was when a fire alarm went off somewhere else in the building, and no procedures could continue until the light stopped flashing, which was an extra 20 minutes or so.
Probably 3 or 4 hours of surgery.