I have the opposite problem in that I can't fall asleep at night. I used to try laying down, but then I'd be lying awake for hours and hours all night long with no sleep until the sun came up. Finally, I just gave up on that and just get in bed whenever I get tired, but it's usually 4 in the morning or later (My clock says 3:15 am as I type). Of course, when I finally do get to sleep, I could easily sleep for the next 12 hours or more, but then I'd give up the whole day.
It's not something new, because I've been like this since I was in late childhood. When I was young, I had normal sleep patterns, then I couldn't sleep, and the only other time I had "normal hours" was during my college years if you can believe that. Then again, that was the only time any of my doctors would give me the pill for the periods that either wouldn't start or wouldnt stop. However, into my mid twenties, I started having a lot of stomach problems, which were worse at night once I had all my food for the day, so it again became easier to deal with that at night and sleep in the day when I was "okay
However, I've had PCOS symptoms since I got my period at age 9, which have finally at age 29 been recognized by a doctor. (Yay!) It's only been in the last week as I've been doing research that I have questioned whether all the hormonal problems could have been associated with the sleep patterns.
I just started treatment today, so I'm anxious to see if that will do anything in helping me learn to get a more normal schedule. I've been on a low carb diet for about a week and a half now, and the best thing I can say about it so far is that I haven't had any of the stomach upsets that I used to have (dumping, bloating, etc.) If nothing else gets fixed in all of this, at least I have one positive thing to be happy about.