In today's episode, we begin our investigation of the individual etymologies of each day of the week. Both "Monday" and "Tuesday" are ultimately loan translations of the Latin word dies lunae (Luna's day) and dies martis (Mars's day), respectively. Luna, the Roman moon goddess, was identified with Mani, the Germanic moon god, and Mars, the Roman god of war, was identified with Tiw, the chief deity in the original Germanic pantheon. But that's just scratching the surface. Both "Monday" and "Tuesday" contain unexpected stories that reveal to us the cultures of our linguistic ancestors.