Please add a rule that blocks subs from seeing or receiving (or being assigned without an admin override) to jobs within a 24 hour window after they have cancelled a job within 24 hours of the job starting. The system could add a non-removable event block to the day of that cancelled assignment or something similar for that substitute. Cancelling within 24 hours only to pick up another job that they deem is better (or more hours) leaves the other school in a bind and sets a bad precedent for those substitutes that will use this loophole.