The Origin of the Chaldean Order and Planetary Days of the Week

In this episode I propose a new theory about the origins of the so-called Chaldean order of the planets, as well as the assignment of the seven traditional planets to the days of the week.

In ancient times, a specific sequence of the planets arose known as the order of the seven-zoned sphere, which goes:

Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn.

In modern times, this is often called the “Chaldean order”, because the 5th-century CE writer Macrobius referred to it as the “system of the Chaldeans.”

For a long time, it was mistakenly thought that this meant it came from ancient Babylonian or Mesopotamian astrologers, but we now know there is no trace of it in that tradition.

In Macrobius’s era, the word “Chaldean” had simply become a generic term for “astrologer”, so when he refers to it like this, what he really means is “the system of the astrologers.”

So, where did this system come from, and when was it introduced?

While historians have long know…