[sliverstorm]

I personally have found, research or no, that shifting my sleep schedule later has deleterious effects on my state of being the following day. I do not sleep less time (I wake later- my internal clock is very reliable about extracting 8:30-9:00hrs of sleep when alarm clocks don't intervene). This holds whether or not I am keeping a regular sleep schedule, have curtains, when I last ate food, etc.

I find I am most effective when I begin sleep at ~11PM.