Why Are the Days of the Week Named After Gods? Most people use the days of the week without thinking twice about them, but in English, they carry traces of ancient mythology. The names we use today are a mix of Norse and Roman traditions , layered over each other through history. In Latin languages (like Italian, Spanish, and French), the days are mostly named after Roman gods and celestial bodies . For example, Lunedì  (Monday) comes from Luna , the moon; Martedì  (Tuesday)