Mine have all been private, so they schedule themselves, though No. 2 has an assistant to do it. I guess I could have the same time every week if I wanted it (No. 2's assistant appears to be trying to do that as much as possible), but I've never wanted it and I'm flexible where other clients' work schedules are fixed. The reason I don't want a fixed time is the variety helps me - I would find being the 10 am Tuesday stultifying.