In answer to the questions, at least in the ER there are mostly 12 hour shifts with occasional 8 hours shifts thrown in, so you might work 3 12's one week, 4 12's another, and 3 12's and 1 8 another...
So before I came down to work in the USVI, I checked around the forums here and didn't find a great deal of specifics. So, as a service to others considering the same, here is some (hopefully) useful...