Ancient Mesopotamian astrologers devised a seven day week inspired by the heavenly bodies that wandered about the sky. There were seven in total. The equally sized flashlight and nightlight in the sky, the sun and moon, along with the other five wandering orbs of light thus form the basis of this alchemical cosmology.
The word planet comes from the Greek planētēs, meaning “wanderer”. So by definition the Sun and Moon were considered planets to the Ancients.
Of the days that are not named directly after the seven planets, their name is derived from the Norse Gods associated with the respective planet. The origin of Sunday is of course from the Sun in the sky. Of the seven known metals, the Sun has always represented gold, irrespective of time and place.
Monday or more properly, ‘Moon-day’, is known as …