I think providers who request "same day" appointments are completely unreasonable. Some of us like to plan everything (including sex) days, weeks, and sometimes months in advance. It's not just a preference; it is ingrained into our personalities. We are not all Myers-Briggs (P)erceiving types, who are known to be much more spontaneous. I happen to be an INTJ, so I prefer to spend about six weeks (at least) planning out every detail of every possible human interaction that I'm going to have during a vacation.
For Christ's sake, I repeatedly go on Google Maps months before a trip just to memorize the street view so that I know every highway entrance/exit ramp, intersection, parking lot, even the sides of buildings the doors are on, so that i know where I'm going every second of the way. A lot of these providers then expect me to wait until the day I want to meet them to plan something?
Nope.