Have you ever wondered where all those references to a magic or important number 7 come from--seven days in the week, 7 wins in dice games, 7 rungs on the Alchemist's ladder? Seven is the number of heavenly bodies in the sky that move about quickly on a regular basis--the sun, moon, Venus, Mars, Jupiter, Saturn, and Mercury. In fact, the word planet is derived from the Greek word meaning wanderer.
When it comes to the days of the week, Sunday for the sun and Monday for the Moon are obvious. Saturday for Saturn is not much of a stretch, but the others are less obvious. With the German barbarian invasion of Rome, Thursday came into play as Thor's Day with his thundering hammer, replacing Jupiter with his lightening bolts, as the symbol for that day. Friday comes from Freya, replacing Venus as the symbol of that day. Tuesday comes from the Germanic god Tiw or Tyr, the god of single combat, replacing Mars as the day's symbol. Wednesday comes from the Germanic god Woden, replacing the Roman Mercury.
Furthermore, each of the heavenly bodies is linked to a metal and appears as a rung on the alchemist's ladder. The top rung is gold for the sun, the second rung is silver for the moon, lead for Saturn, tin for Jupiter, iron for Mars, copper for Venus, and mercury for the planet Mercury.
When you think of the 7 days of the week, I hope you will have a new more historic take on them. It turns out they are heavenly days. As the dice players say, "Come on seven!"