I agree that this T's policy is too inflexible to be workable for most people.

My T's official policy is to charge for a full session with less than 24 hours' notice and he reviewed that with me in my first session. Since then, though, he's told me that it really is flexible and that if I wake up sick as a dog or some other emergency arises, I can cancel without charge. If it becomes a pattern, then it becomes chargeable and a topic for discussion in therapy. We make appointments week to week, but unless one of us has something unusual arise, we meet at the same time.