You should fix and keep your daily schedule. I was a night owl. It seemed golden time to concentrate on tasks I had to do. I could handle lots of homework in fact. However it made me be hard to get up in the morning, and I couldn't all things I should do in the daily time. It left me more homework and I should keep awake later. It was a kind of vicious cycles and my productivity was decreasing at all. After I realized this fact, I decided to set and keep my routine. Sometimes it's hard to keep, but it basically brings me a good sleep experience.