[5.points]

Originally Posted by MrRubix

Check this out when you get a chance: http://en.wikipedia.org/wiki/Delayed...phase_syndrome

And check out the fixes and see if those help

This would be a likely reason but DSPS is more long term.

I have DSPS and have rarely ever fallen asleep at night, no matter what time zone difference, until daytime came around (cloudless days are worse). It tends to happen more in the winter and summer when daylight hours are weird. I had to adapt to falling asleep early and wake up early in the morning and getting stuff done.

It could just be stress. In that case you could just do something boring or take something to sleep.