Tuesday - Saturday are Norse/Germanic/Roman Gods and Sunday/Monday are named for planets.
Monday - Moon's day Tuesday - Tiu's 日 ( Germanic version of Tyr, the Norse God of War/Sky) Wednesday - Woden's 日 (Germanic version of Odin, Norse King of the Gods) Thursday - Thor's 日 (Norse God of Thunder) Friday - Freya's 日 (Norse Goddess, leader of the Valkyries) Saturday - Saturn's 日 (Roman God of agriculture) Sunday - Sun's day