Multiple Command Crews?

Shouldn't starships have more than one command crew? Whenever you see the Enterprise D/E's bridge you almost always see Picard, Riker, Worf, Data, etc, etc... other than Data these people all need time to sleep and time off from duty, so who commands the ship while they're asleep or on a break? (as they all appear to work/sleep at the same time)

They should have a night shift/day shift rotation of at least the 4 main officers, with the other crew spots on three 8 hour rotations or four 6 hour rotations.

I know shift rotations have been mentioned once or twice in various series, but the issue of a relief Captain or night shift Captain has never cropped up.

It's been on a couple of times. In several episodes of TNG you see Data be the night shift captain. But I guess there is probably some other officers who aren't regular characters who take command.

I wonder who takes command when they do stupid things like in Nemesis where the away team consisted of everybody (Picard, Riker, Troi, Data, Worf, Crusher, La Forge)

They usually have the next in charge take the bridge. And extras manning the other stations.

What I don't get is sometimes they have the "night shift" scenes and the person talks about how boring it is like it's actually night. Do they park or go someplace safe while the main crew sleeps or is the universe pretty quiet after eleven?

More than likely, crews of the ship work in 24 hour shifts, so a 'night crew' would be almost the same as a skeleton crew. You wouldn't have the same amount of people working around the clock, instead you would have a main crew, which works during the 'day', and other crews who take up the evening/night shifts. So, someone who is in command of the night shift would have less responsibilities, since their crew complement would be smaller. After all, you can't have the Enterprise zipping around the galaxy and doing her regular missions while the CO and XO are asleep in their quarters. Not to mention fully manning a ship 24/7 would require an IMMENSE amount of personnel. Day/Night crews are make perfect sense.

And as others have posted, in TNG, DS9, and Voyager, there have been night shifts shown.