With my T it is exactly 45 minutes from the moment he responds to the door bell until I'm out of the room. It takes me about a 1-1.5 minutes from entering the front door until I'm laid down on the couch and it takes up to minute to put my shoes and jacket on and get out of the door. So the effective session time is about 42-43 minutes. The session never starts earlier and it never runs longer.