The Clark Planetarium is only closed on two days out of the year - Thanksgiving and Christmas. It does have shorter hours on Christmas Eve. Shorter hours - only one shift that day. And it isn't very busy that day. So the staff that day is basically there on a paid volunteer basis. Because my family doesn't do much on Christmas Eve, and what little we do do is generally at night, I volunteered my second year there. It was a pretty decent time, and we got free food. As we typically did when working any sort of holiday.