Exactly, if you find a way to know which makes you feel better, whether it's working during the day or working during the night, then you will find it very easy to pick the one you want and get on with it. Some people work less during the night while some work more during the day.
I am always useless at night as far as working is concerned. I don't joke with my sleep and there are times that people will wonder why I sleep in that way, but that's how I want to live. I will always struggle to work better during the night.