Yes, I agree it starts at the point you knock on the door and the SP will no doubt make a mental note. I had a poor encounter recently where I knocked four minutes ahead of the agreed time as it was freezing cold plus I didn’t have long to catch a train afterwards.
The SP, who was putting in a half-arsed effort, made sure to point out half way through that my appointment would end five minutes early because of my arrival time. I hadn’t been trying to wangle the additional minutes, but that seemed to be her assumption. It was one of a number of similar comments that killed the mood.
Obviously many factors can influence how quickly they turf you out at the end (how soon they have another booking etc), but I think it can make a world of difference when an SP isn’t running a conveyor belt service and doesn’t feel the need to time you to the second!
After another recent encounter, I was dressed and ready to leave on the hour mark but ended up being a full 20 minutes late as the SP wanted to chat about her travels (we’d been to a number of the same places). I like it when I come out of a booking feeling like I’ve met a real human being rather than a machine, but of course every SP is different and their circumstances vary.
My query is always whether a shower at the end comes out of your paid time. I guess it should really to be polite, but apologies if that is taking the thread off topic.