C.O.
I'm dealing with the same thing with my 16-month-old. He was up at 4:15 this morning!
For us, I think it's mostly the earlier sunrise that's causing the problem. I'm working on getting dark curtains up.
Another thing that helps is to feed him right before bed. Oatmeal is a great pre-bed snack: it fills him up and helps him stay full longer.
Good luck!