It's down to your chronotype, according to recent research.

Everyone has one and it basically boils down to your body's ideal sleep schedule. Some people are more predisposed to going to sleep earlier and therefore walking up earlier (10pm-6am is a pretty common one apparently), others are more predisposed to a later schedule such as 2am-10am. Some people need longer, some need less.

The big thing is, you can force yourself out of what your body would prefer, but it's pretty much always at the cost of alertness and mood and it will never feel natural.

The problem we have now though is the 10pm-6am crowd has the world designed around their schedule with the incorrect assumption that everyone should just do what they do and it's just poor discipline preventing others from getting on board.

No amount of blue light filters, digital hygiene and eating earlier is going to change your body's preference, unfortunately.