Nocturnalsexual is a term for those who feel that their sexual attraction is stronger at night and weakens at daytime or simply doesn't exist during daytime.
One who is nocturnalsexual may or not feel that their sexual attraction increases when simply thinking about the night or playing a game in which it's nighttime, as an example.
History
Nocturnalsexual was coined by FANDOM user NyxIsSus after discovering that Nocturnalromantic did not have a sexual counterpart.