Nocturnalromantic is a term for those who feel that their romantic attraction is stronger at night and weakens at daytime or simply doesn't exist during daytime.
Flag
The flag was designed by FANDOM user Reign of the breadsticcs on April 10, 2021. It represents romantic attraction being weaker or nonexistent during the day (the thinner, lighter blue stripes), and it increasing as nighttime arrives (thicker, darker blue stripes).