So here is the problem. The Dean or Associate Dean at your School is making up the schedule for the fall. Nearly everyone wants to teach in the time period from 10-2 on Tuesday - Thursday and so indicate on a form that asks for their preferences. There are not enough rooms and, even if there were, there would be conflicts that mean students would have to make choices. The conflicts would not occur if classes met earlier or later or on Fridays and Mondays. The Dean sends out a schedule that has Professor X teaching on Wed - Fri at 3:00 even though Professor X said he prefers the same times as everyone else. Professor X is no different from anyone else with respect to his "need" not to teach on Friday.An exchange of emails occurs with X saying "I do not teach on Fridays." Literally, it is possible for X to teach at his preferred times but, again, it would mean students could not take his course and another also scheduled at that time.
I am not sure exactly how to pose the question but the generalized idea is what can/should a dean do. Can a Dean order people to teach at a certain time? Here is a non exhaustive list of possibilites: