Why the Week Has Seven Days

Why the Week has Seven Days

No more logic supports seven days than, say eight or five, yet the seven-day week has resisted any and all attempt at change.

Unlike the year and the month, which correspond to the movements of the earth around the sun and the moon around the earth, the week has no astronomical analogue. Seven days is roughly the same length of a phase of the moon (seven days, nine hours) but any system of timekeeping quickly falls apart due to the extra hours piling up.

Officially adopted by the Emperor Constantine in A.D. 321, the seven-day week goes back thousands of years. Here’s some history…

  • The seven-day week started with the first civilizations of the Middle East. Mesopotamian astrologers designated one day for each of the seven most prominent objects in the sky—the Sun, the Moon, and the five major planets visible to the naked eye.
  • The Jews also adopted a seven-day cycle, based on the time it took the Lord to create the universe as reported in Genesis. A new wrinkle in their week was the Sabbath, a day set aside for rest. This was the first time a culture had invented a holiday that occurred on a regular basis, unrelated to natural phenomena.
  • The Romans adopted different weeks for business reasons; they thought of a week as the 8 days between market days.
  • West African societies preferred a four-day market cycle.
  • In Assyria, 6 days was the rule; in Egypt, 10; in China; 15.
  • The ancient Germans used a five-day cycle named for their primary gods which is how our week ended up honoring Norse deities like Tiw (Tuesday), Odin (Wednesday), Thor (Thursday), and Frigga (Friday). Our word “week” may come from the Old Norse word vikja, which means “to turn.” Sunday and Monday, or course, honor the Sun and the Moon.

Atheistic revolutionaries tried, unsuccessfully, to get rid of the seven-day week. In 1793 the leaders of the French Revolution produced a new calendar divided into three ten-day “decades.” It never caught on, and Napoleon abandoned it in 1805.

In 1929 the Soviet Union tried a five-day week, with one day of rest.

  • Instead of the traditional day names, the days were given colors: yellow, orange, red, purple, and green.
  • In order to keep mass production going, each Soviet citizen was assigned a different day of rest, so that a husband might have a yellow day off, while his wife took her leisure on green.
  • Due to mass confusion, the plan was revised in 1932 to a six-day week, with numbers replacing the colors.
  • By 1940, the Russians were back on the familiar seven-day cycle!

Somebody was always trying to come up with something better! In 1936 the League of Nations solicited proposals for world calendar reform and considered almost 200 different schemes, many of which rearranged the week.

  • Edward Skille of Drummund, Wisconsin, suggested a year consisting of 73 five-day weeks called “metos.” The days of the week would be called Ano, Beno, Ceno, Deno, and Eno.

Why the seven-day week? It doesn’t divide evenly into 365- or 366-day years, so that holidays fall on different days of the week from year to year. But human beings are not logical creatures. Who can imagine saying, “What are you doing next purple?” or “Yeah, it’s Eno!”

As one member of the British Parliament remarked in a 1944 debate on calendar reform, “It is bad enough to be born on April 1, but to have one’s birthday always on a Monday would be perfectly intolerable.”


The 1988 Old Farmer's Almanac

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"In the beginning God created

"In the beginning God created the heavens and the earth."( Genesis 1:1) . This opening statement of the Bible stands alone, indicating no distinct period of time related to the creation of "the heavens and the earth."( A reference to the entire universe) From verse 2 onward, Genesis chapter one discusses the six creative 'days' during which God evidently prepared the-already-existing-earth for human habitation. These six creative 'days' could have lasted for thousands of years. The Bible account of creation, thus, does not conflict with scientific conclusions about the age of the universe. [Compare Genesis 2:4 for the figurative use of the word "day."]

"In the beginning God created"

Well stated L Maunder. The bible does not state how long it took God to "create the heavens and the earth."(Gen 1:1) However after it became "without form, and void"(Gen 1:2) it took God 6 days to put it back together in a state to be inhabited. And then he rested on the seventh day.

'The Jews also adopted a

'The Jews also adopted a seven day week, based on the time it took the lord to create the universe as reported in Genesis" -- or vice-versa
Isn't it more logical to believe that Genesis was written by the Jews under the assumption that it took the lord one seven day week to create the universe!

logic has nothing to do with it

The first five books of the Old Testament were written, not by "the Jews", but by one Jew - Moses. From the incident of the burning bush forward, Moses was in regular, sometimes daily communication one-on-One with God Most High, the God of Abraham, Isaac, and Jacob. Genesis, Exodus, Leviticus, Numbers, and Deuteronomy (except for what happens after Moses' death) are the work of this one man, and based on what God revealed to him. That includes not just the law, but the entire history of man on this earth, gradually focusing on the descendants of Abraham. As to the age of the earth, God did not create Adam an infant - he created him a fully grown adult. In just that same way, He could easily have created the earth to also be mature and ready for human life. For a God who can speak the most intricate, complex systems into creation, doing all that in six days is in no way a stretch.

If the week had 10 days, it

If the week had 10 days, it would make sense. You have 3 10-day weeks.