Salamu alaikum. Brother, is there a thing such as a "nocturnal person"? What do you think of such person who is wide awake at night and sleeping during the day? Is it mentioned in the Quran whether it is prohibited or not?

Alaikumassalam wa rahmatullah,

That is often caused by having caffeine late in the day. As for the Islamic view, I know of no Quranic verses or hadiths that apply directly to it.

During Ramadan I often stay up the whole night until fajr because I am unable to work (programming and writing) when I am fasting, and to avoid spending an entire month unproductively, I switch my schedule so that I stay up at night and sleep during the day. I know some preachers speak against this, but since there is no clear evidence against it, and since my intention is not to avoid the difficulties of fasting but to be able to work, I believe it is fine.