I usually have my bag in hand five minutes before time is up (going by my watch). CW doesn't seem a real stickler for finishing on the dot. In fact, I think that the more obviously anxious I am to leave, the more any therapist is determined to keep me there.

I didn't encounter 15 minutes after the hour appointments until I started using insurance (45 minute appointments are what they cover). Makes me think of a line in "The Prime of Miss Jean Brodie," about how people who make quarter-hour appointments are trying to intimidate whoever they're meeting with.