I currently have a sleep schedule similar to your previous schedule... work until I'm done with projects, usually Midnight to 2:00 am, sleep until 9 or 10 am. However I've noticed recently that I wake up nearly every night around 5 am, regardless of when I go to bed, and then I lay in bed irritated that I can't get back to sleep until around 7:30 am, then I doze off and wake up again around 10 am. So based upon your comments, and the article, I'll try getting up when I wake around 5 am and doing something productive, and then go back to bed around 7:30 am and get a few more hours of sleep. I don't know why, but I would have never considered doing that, I guess because I'm always irritated that I can't sleep in the middle of the night. My work environment would allow me to nap during the day, but I find it uncomfortable to sleep during the day.