How Did the Days of the Week Get Their Names?
Weekdays were named in honor of the sun and moon, and for the ancient gods. The Romans named the first two days of the week after the sun and moon, and so they are called Sunday (sun’s day) and Monday (moon’s day). Tuesday is the day of Tiw, the Old Norse god of war. Wednesday is “Woden’s day,” for Woden, chief of the gods. Thursday is named for Thor, the thunder god, and Friday honors a beautiful goddess named Frigg. The Romans called the last day of the week “Saturn’s day,” in honor of the god Saturn. Today, it is known as Saturday.
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 Germanic peoples generally substituted roughly similar gods for the Roman gods, Tiu (Twia), Woden, Thor, Freya (Fria), but did not substitute Saturn.