The Greeks named the days week after the sun, the moon and the five known planets, which were in turn named after the gods Ares, Hermes, Zeus, Aphrodite, and Cronus. The Greeks called the days of the week the Theon hemerai, 'days of the Gods'. The Romans substituted their equivalent gods for the Greek gods, Mars, Mercury, Jove (Jupiter), Venus, and Saturn. The Germanic peoples generally substituted roughly similar gods for the Roman gods, Tiu (Twia), Woden, Thor, Freya (Fria), but did not substitute Saturn.
- Sunday: Sun's day.
- Monday: Moon's day.
- Tuesday: Tiu's day. Tiu (Twia) is the Germanic god of war and the sky.
- Wednesday: Woden's day. Woden is the chief Germanic god.
- Thursday: Thor's day. Thor is the Norse god of thunder.
- Friday: Freya's day. Freya (Fria) is the Germanic goddess of love, beauty, and fecundity.
- Saturday: Saturn's day. Saturn is the Roman god of agriculture.
