My BIL is one. He works 24 hour shifts (I don't know if it's one day on, two off, or how it works,) but my point was, they don't normally work three shifts a day like many places do, so "switching to midnights" wouldn't even be an option.<quoted text>
My friend's husband is a firefighter. He works 10 days on and 10 days off. I have no idea how standard that is...
