I worked the graveyard for about 1. 5 years. The longer I was on it the less sleep I would get. Spring time was terrible. Get home at around 9 am, on a nice, sunny, warm morning. There's no way this farm boy was going to let a nice, sunny day go by sleeping! I worked monday nite-to friday night. Try being 22 and leave all your buddies that were ready to go out night wheeling on a friday night, to go to WORK! For some reason a lot of sick time was used on friday nights. The fridays I did go to work was almost always followed by an all day of wrenching on trucks. About noon on Saturday I had to appoint someone to watch me and think for me. As long as I kept moving-everything was cool, but thought process was blurry or nonexistent. Then saturday afternoon-evening we would fire up the trucks and wheel all night until 3-4am sunday. Then I could sleep good Sunday and Monday.
Then I ended up with a girlfriend and her little boy. They would be home at 4-5 pm, and I could not sleep when they were around. Just a little noise and sleep would stop. Then I started getting home from work, pull in the driveway and could not remember any of the trip home. I could remember leaving the shop, and find myself in my driveway. I would walk around the truck just to make sure the sheetmetal was still straight. !
When that started happening, I started looking for a new job. Now I work days=much better.
Get in a groove and stick to it. Work hard-play hard, then you usually sleep well too. Night shift was great because I did not have to work hard, but was still very productive. No interuptions. It however was not worth the extra $. 75/hour.
Good luck, be safe. When you get tired-sleep. Its not worth getting hurt for. While at work, occasionally I would come out of the "fog" and realize I was doing something very stupid, dangerous, life threatening, and scare myself!

Wasn't worth it.
Once again- be safe.
Michael