I've been working full time at a restaurant and I recently requested Sundays off for reasons I don't feel comfortable disclosing to my manager.
They told me full weekend availability was a condition for all new hires (even though we hadn't discussed it in my interview, just that I can expect to work anywhere from 25-40 hours a week.) but they would do their best to accommodate me. But this isn't a time off request, it's a change in my availability.
Is there anything I can do to protect myself in the event that I'm scheduled and can't show up?