History of the Weekdays

By the third century the seven-day week had become common in private life throughout the Roman Empire. Each day was dedicated to one of the seven planets. Those seven, according to the current astronomy, included the sun and the moon, but not the earth. The order in which planets governed the days of the week was: sun, moon, Mars, Mercury, Jupiter, Venus, and Saturn. This order was not that of their then supposed distance from the earth, which was the "normal" order in which Dante, for exampl...