I work away from home a lot on the rigs. Well, not a lot, of time or work to be fair. But I am usually on my own, so generally do a 12-24 shift if I can. At the end of the shift I usually eat / smoke then watch a movie. If I'm not alone, I'll try to do nights as that's usually where the actual work happens, but also there are less important people kicking around.
But at home, as I am now, I generally find myself going to bed anytime between 0200 - 0400 depending on how I'm feeling. Usually up around 0900 though. I do have 2 kids, but my wife takes the morning shift, and I do the night shift. They aren't the best sleepers (like me I guess).
I generally blame my first proper job. I used to work a back-shift, so was 14:30 - 23:00 roughly (IIRC). Did that shift for years. So I usually slip back into a similar sleeping pattern to that. I hate getting up early for actual work if I'm required to do so. But can generally manage ok. I find as long as I get around 6 hours sleep I'm ok. But usually much less than that for the first couple nights on dayshifts.