I have recently become a fan of Firefly, which as many of you probably know is really bad timing.

But in one particular episode they make reference to it being night time. This always bugs me about shows set in space.

While I can see why you would want to create an artificial time of day for the sake of sanity, there is no reason to believe that anyone else in space would be on the same schedule.

It always seems like all the major characters are active during the same shift, so who runs the ship at "night".

It was just lucky that the Klingons never attacked the Enterprise while the night shift was on duty.