Question: Where did the names of the days of the week come from?
Answer: The Babylonians tracked the Sun, Moon, and the five planetary bodies known to them. They believed that each of these seven celestial bodies was ruled by a god or goddess, who also shaped events on Earth. In the seven-day week of the Babylonian calendar, each day was influenced by a particular god or goddess.
Greeks from the Hellenistic period also created a seven-day “planetary” week, naming the days after their own deities (Helios, Selene, Ares, Hermes, Zeus, Aphrodite, Cronos).
The Jewish week was (and still is) also divided into seven days, but instead of being based on the planets, this system was tied to the account of Creation in the Hebrew Bible. These days had numbers, not names, with the seventh day being the Sabbath.
Influenced by these cultures and ideas, the ancient Romans eventually dropped their eight-day week and adopted a seven-day week, basing the day names on the known planets, Sun, and Moon and their own deities. This seven-day week system spread to other civilizations, which sometimes adjusted the names to their own language and beliefs.
In Old English, “Sunday” comes from Sunnandaeg, or Sun’s day, followed by “Monday” which stems from Monandaeg, or Moon’s day. The rest of the day names with which we are familiar stem from Anglo-Saxon names for gods in Teutonic mythology. Tuesday, or Tiwesdaeg, comes from Tiu, or Tiw, the Anglo-Saxon name for Tyr, the Norse god of war. Wednesday, or Wodnesdaeg, refers to Woden, or Odin, the supreme deity. Similarly, Thursday, Thursdaeg, originates from Thor, the god of thunder (corresponding to the Roman god Jupiter, or Jove). Friday, or Frigedaeg, is derived from Frigga, the wife of Woden and goddess of love and marriage. Saturday, or Saeterndaeg, refers to Saturn, the ancient Roman god of agriculture, fun, and feasting.