Then, make them pay an appropriate misery tax if you don't want them and just have to support. You're paying your own to suffer them. I've heard of fairly wily ones where a Director took a known semi-controlled diabetic and with the schedule, she see-sawed the pharmacist late, late, day, day, day, late, until he decompensated and was medically retired or screwing around with vacations and leave on necessity (always around school vacations) that indirectly caused a divorce to get rid of her Assistant Director. Trust me, there's a deep well of sadism creativity that you can plumb if you really want to. Not that I would ever advocate such a solution, though I've had my own encounters to survive with that...
What I learned from that Director:
1. Never put personal events on a work calendar (because your Director will spy on it).
2. Never disclose any of my health conditions to supervision or anyone at work.
3. Never discuss why I'm taking vacation when with anyone or be visibly looking forward to it if cancellation is a possibility.
4. Strategically take sick leave if someone is intentionally trying to break your Circadian.