When I code, I can clearly see how productive I am based on what time of day it is. I have spoken to many others about this very topic and notice that many people have different times that they are highly productive. For example, my friend is at his most productive between 8PM and midnight; I am at my most productive between the hours of 11AM and 2PM.
Knowing what time you are most productive is important to help you plan your day. If you get the most work done between 6AM and 8AM, maybe you should wake up earlier so that you can get your work done in the most efficient manner. This will allow you to free-up more time from your day to put towards other things.
Because I am most productive between 11AM and 2PM, I dedicate those three hours to coding, while I plan to do other menial tasks at other times of the day. It is important to note that the average maximum length of time someone can focus with success is between twenty and forty-five minutes. Due to this, it is important to take breaks, even when you are trying to be productive. I understand that it is quite counter-intuitive, but the best way to get ahead is to take breaks and relax when you notice yourself starting to lose focus.