I have seen two therapists, one who never gave me a set time and it varied greatly from week to week and one who gave me a standing appointment time at 6pm every week. I MUCh prefer the standing appointment time for several reasons, consistency and reliability being the most important. I also like that no one comes after me because on rare occasions we run over just a little. In the winter months it is dark when I arrive but I don't mind. Oh yes, and no one else is in the building which is important for me as I find unexpected movements around the office very triggering.