What is the best time to study: day or night ? Why?

It is usually best to study on a quiet place during daytime. Under normal circumstances, cramming usually happens when you study at night before the exam and besides, the brain is more functional when it is well rested while you were sleeping at night. And it is really hard to focus if you are too sleepy and you feel like the bed is calling you.

for me not important the sched the must is i unerdstand what i preparing to annalys.

Surely, day time, and here is not even a question - day os for activity, night for sleep