Melatonin supplements have been putting me through college. I don't know if I have a non-24-hour sleep cycle, delayed sleep phase syndrome, or I'm just lazy (I think it's the first choice), but until I discovered melatonin supplements about a year ago, my sleep schedule was hopeless. Now, I have no issues whatsoever.

http://en.wikipedia.org/wiki/Non-24-hour_sleep-wake_syndrome Isaiah 34:14