nocturnal to diurnal

I've gotten practically nothing done this week- it could be any number of things (post-Spring Break fatigue? Post-quals fatigue? The fact that the dosage of the drug that controls MY METABOLISM has changed four times this year?)

But I really think it has more to do with the fact that in college, my best working time was from 10 pm to 2 am, and now it's... sometime else. I'm not sure when, but it doesn't seem to be in the morning, the afternoon, or at night. I'm looking for it. It could be the years of teaching that made me get up early every day, or just being 28 years old, but I'm no longer a nocturnal worker. Also, I may just be lazy.