My T works three days/week and after nearly a decade in the community, his slots are usually full, except if it's one of the weeks that people often take off-- holidays, school closings, etc. He will say that he will put me on the cancellation list and about 3/4 of the time this will result in an appt that same week. I have probably asked for about 4 emergency sessions in the last year, and only recall one where he wasn't able to fit me in. He might have also just stayed later one day on at least one of those requests.