I've been working rotating day-night 12 hour shifts for 18 years. (In my part of the world we don't have a choice, in acute we all work rotating shifts, pretty much.) It's not impossibly difficult if it's planned properly. One night by itself doesn't mess up sleep patterns much, but only having 36 hours off between ending a night shift and beginning a day shift does. The best scenario is 2 on, 3 off, regardless of day or night. It's also better (healthier) to do a stretch of one shift over a couple of weeks. If your manager is determined to have you rotating, negotiate a schedule that will allow you to have some real down time between sets of shifts.