The Origins of the Week Day Names

The Order, Sequence and Arrangement of the Week Days

by Joseph Buchmann

The origin of the week day names is fascinating. The history behind the established sequence of the day names is simply mind-boggling. We know that the names of all the seven days are related to celestial bodies, the moon, planets and stars. Most day names in the Roman languages clearly reveal the linked star. In the Germanic languages, the days relate more to the Gods or Goddesses that are associated with the star. We will now explore the perplexing sequence of the week day names.

In the ancient world, only seven of these heavenly objects were known by name and revered. The planets Uranus and Neptune were yet to be discovered. Each of the seven stars was sacred and each was the embodiment of a God or Goddess. Each new day was devoted to a Star God, in a seven day rotation.

The seven known God Stars have traditionally been listed in the order of the length of their orbits, the elapsed time before there reappearance. For the sun, it was the annual cycle of the world's seasons. Thus, the lineup was:

Moon: 29 days (dies Lunae, Monday)
Mercury: 88 days (dies Mercurii, Wednesday)
Venus: 225 days (dies Veneris, Friday)
Sun: 1 year* (dies Solis, Sunday)
Mars: 2 years (dies Martis, Tuesday
Jupiter: 12 years (dies Iovis, Thursday)
Saturn: 29 years (dies Saturni, Saturday)

But why are the names of the week days not in that same traditional order? They seem set in a random order. Why is the day of Mars before the day of Mercury. Why is Tuesday before Wednesday? The reason behind the odd sequence of the week days is altogether astonishing and eye-opening.

First, we must dig into some background. As early as four thousand years ago, the ancient Egyptians split the day into 24-hours, a 12 hour day, and a 12 hour night. Time devices, such as shadow clocks, marked 5 hours as the sun ascended and 5 hours as the sun descended. A twilight hour was added in the morning and again in the evening, making a total of 12 hours of daytime.

In ancient Egypt, each hour of the day and night was dedicated to one of the seven known heavenly stars, each the embodiment of a God and Goddess, feared or benign. The hourly dedication proceeded in the strict order of the stars' orbital lineup. There were only 7 God Stars but 24 hours, so every seven hours the cycle repeated itself. The first hour after midnight was primary and dominant. Number 7 does not evenly divide into 24, and the pick of the day's first hour thus shifted out of order. The God or Goddess of the first hour owned the new day, and the new day was named after Him or Her.

This animated Gif image demonstrates the drill and workings.

Week Days


Why was the number 12 so important? Perhaps it is the number of the twelve moon cycles in a year, perhaps because it is a convenient number, divisible in so many ways. A theory has been brought forward that the number 12 is linked to the ancient practice of finger bone counting in Mesopotamia. With the thumb of one hand, people counted the bones of the four fingers; four fingers, each with three bones, a count of 12. With the five fingers of the other hand, they tracked and added up the full counts of 12, for a grand total up to 60. This counting method may be the foundation of the Sexagesimal (base 60) numbering system used by the Sumerians and Babylonians, a system that amazingly we still use today when referring to degrees, minutes and seconds. However, the finger bone dabbing theory may fall apart when we look into the makeup of Babylonian cuneiform numbers. Cuneiform numbers, although based on the Sexagesimal system, clearly use wedge symbols for units of 10, but none for units of 12. Perhaps finger bone counting predates the cradle of cuneiform writing.

In Roman-influenced languages, most weekdays still carry the name of a star; in the Germanic languages, many of the days took on names of Germanic pagan, like Tiw, Wotan, Thor, Frigg. There are some logical connections. Both the pagan Gods Tiw and the Mars are Gods of War. There are known associations between Gods Wodan and Mercury going back to Roman times. Thor and Jupiter are both Gods associated with Weather, and Friig is the Goddess of love and lust, in the image of Venus.

Monday: Named after the Moon

Tuesday: Named after the Germanic god Tiw, the god of single combat, god of war and law. God Tiw is associated with the Latin god Martii, equated with Mars. The French name for Tuesday is 'Mardi' for mars.

Wednesday: Named after the all-important Germanic god Wodan. The Romans identified Wodan with their god Mercury. The French name for Wednesday is 'Mercredi', for Mercury.

Thursday: Named after the god of Thunder, god Thor, associated with the Roman god Jupiter, god of skies and thunder. "Iovis dies", Jupitor's day, became the French day name 'Jeudi'.

Friday: Named after the goddess Frigg, associated with the Roman goddess Venus, goddess of love, lust and fertility. The French name for Friday is 'Vendredi" for Venus.

Saturday: Named after Saturn.

Sunday: Named after the Sun.

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Origins of Week Day Names

Order, Sequence, Arrangement of Week Days