# Where Did the 7-Day Weekly Cycle Originate? **URL:** \ **Category:** Factual Questions\ **Created:** [October 2, 2003, 9:30am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087 "2003-10-02T09:30:17Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Jim\_B](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jim_b/32/4338_2.png) [@Jim\_B](https://boards.straightdope.com/u/Jim_B)\ **Post date:** [October 2, 2003, 9:30am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/1 "2003-10-02T09:30:17Z")
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday. Then the whole cycle repeats itself. This has been going on for at least hundreds of years. But where (or more specifically _when_) did it originate? Yes, I know Creationists feel it originated 6000 years ago with the alleged Creation of the world. But I assume most of the people on these boards are not Creationists (no offense to the people who are 🙂 of course). ---
**Author:** ![Cillasi](https://avatars.discourse-cdn.com/v4/letter/c/71e660/32.png) [@Cillasi](https://boards.straightdope.com/u/Cillasi)\ **Post date:** [October 2, 2003, 10:02am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/2 "2003-10-02T10:02:58Z")
From: [http://webexhibits.org/calendars/week.html#SECTION00610000000000000000](http://webexhibits.org/calendars/week.html#SECTION00610000000000000000) Digging into the history of the 7-day week is a very complicated matter. Authorities have very different opinions about the history of the week, and they frequently present their speculations as if they were indisputable facts. The only thing we seem to know for certain about the origin of the 7-day week is that we know nothing for certain. The common explanation is that the seven-day week was established as imperial calendar in the late Roman empire and furthered by the Christian church for historical reasons. The British Empire used the seven-day week and spread it worldwide. Today the seven-day week is enforced by global business and media schedules, especially television and banking. The first pages of the Bible explain how God created the world in six days and rested on the seventh. This seventh day became the Jewish day of rest, the sabbath, Saturday. Extra-biblical locations sometimes mentioned as the birthplace of the 7-day week include: Babylon, Persia, and several others. The week was known in Rome before the advent of Christianity. There are practical geometrical theories as well. For example, if you wrap a rubber band around 7 soda cans (or any other convenient circular objects). You get a perfect hexagon with the 7th can in the middle. It is the only stable configuration of wrapping more than 3 circular objects. Four, 5, and 6 objects will slip from one configuration to another. Ancients wrapping tent poles, small logs for firewood, or other ciruclar objects might have come upon this number and attach a mystical significance to it. One viable theory correlates the seven day week to the seven (astrological) “planets” known to the ancients: Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn. The number seven does not seem an obvious choice to match lunar or solar periods, however. A solar year could be more evenly divided into weeks of 5 days, and the moon phases five-day and six-day weeks make a better short term fit (6 times 5 is 30) to the lunar (synodic) month (of about 29.53 days) than the current week (4 times 7 is 28). The seven-day week may have been chosen because its length approximates one moon phase (one quarter = 29.53 / 4 = 7.3825). ---
**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\ **Post date:** [October 2, 2003, 10:03am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/3 "2003-10-02T10:03:55Z")
The seven-day week was introduced in Rome in the first century A.D. by Persian astrologers. The idea was that there would be a day for each of the five known planets, plus the sun and the moon. ---
**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\ **Post date:** [October 2, 2003, 10:06am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/4 "2003-10-02T10:06:04Z")
I should add that Jews were using seven-day weeks by the tenth century B.C. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 2, 2003, 11:13am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/5 "2003-10-02T11:13:46Z")
I’ve responded to this more than once on the Board. My personal theory – the lunar month has close to 28 days in it. The moon has (roughly) four phases in that time – Full, New, First and Last Quarter. Twenty Eight divided by four is seven. Therefore, the 7-day week. The only other division is into 14 and 2. A “fortnight” already is a division of time (although inconveniently long, and not used nowadays). Nobody I know has made the experiment of grouping time into 2-day periods. But I suspect that they’re so close to single days that it’s not worth the trouble. Twenty nine isn’t divisible by anything. I’ll bet that if they went to thirty day “months” we would see five or six day “weeks” (with two more lunar phases thrown in). But it didn’t work out that way. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [October 2, 2003, 1:11pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/6 "2003-10-02T13:11:57Z")
[Cecil weighs in.](http://www.straightdope.com/classics/a2_166.html) ---
**Author:** ![Apollon](https://avatars.discourse-cdn.com/v4/letter/a/e47774/32.png) [@Apollon](https://boards.straightdope.com/u/Apollon)\ **Post date:** [October 2, 2003, 3:20pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/7 "2003-10-02T15:20:56Z")
The days are mostly named after pagan gods in German: Sonntag from Sonne (Sun); Montag from Mond (Moon); Dienstag from Odin; Mittwoch simply means “middle of the week”; Donnerstag from Donar. Apparently, the original English word must have been Thundersday (from thunder, Donar’s main occupation, so to speak), Thursday being an abbreviated form. Freitag from Freya. That most English names for the days derive from the same sources seems pretty obvious. The exceptions are Saturday (apparently from Saturn) and Wednesday (no idea where that came from). So it is likely that the 7 day cycle has been invented independently in several cultures. ---
**Author:** ![Bookkeeper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bookkeeper/32/281_2.png) [@Bookkeeper](https://boards.straightdope.com/u/Bookkeeper)\ **Post date:** [October 2, 2003, 4:06pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/8 "2003-10-02T16:06:02Z")
The sources of English weekday names are generally given as: Sunday = Sun day Monday = Moon day Tuesday = Tyr’s day (nordic god of war) Wednesday = Woden’s day (Woden is Germanic version of Odin, nordic chief god) Thursday = Thor’s day (nordic god of thunder) Friday = Freya’s day (wife of Odin, ferility godess) Saturday = Saturn’s day (Roman god of agriculture) ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [October 2, 2003, 4:19pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/9 "2003-10-02T16:19:08Z")
> [@](#): > > _Apollon_: > > Freitag from Freya. > > _Bookkeeper_: > > Friday = Freya’s day (wife of Odin, ferility godess) Alas no. Freitag/Friday is named after **Frigg** , the wife of Odin and [the goddess of motherhood, fertility, love and housework](http://www.wikipedia.org/wiki/Frigg). ---
**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\ **Post date:** [October 2, 2003, 4:20pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/10 "2003-10-02T16:20:40Z")
> [@](#): > > \*Originally posted by CalMeacham \* > \*\*the lunar month has close to 28 days in it. The moon has (roughly) four phases in that time – Full, New, First and Last Quarter. \*\* The moon has roughly 28 phases. To divide them into four is just arbitrary. ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [October 3, 2003, 9:17pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/11 "2003-10-03T21:17:21Z")
Interestingly, the Bengali names for the days of the week match up with the planets – Robibar - Sun’s day Shombar - Moon’s day Mongolbar - Mars’s day Budhbar - Mercury’s day Brihoshpotibar - Jupiter’s day Shukrobar - Venus’s day Shonibar - Saturn’s day I wonder how exactly the Indian and western weeks were made to matchup so closely. Was one perhaps modeled on the other? ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [October 3, 2003, 11:19pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/12 "2003-10-03T23:19:41Z")
> [@](#): > > I wonder how exactly the Indian and western weeks were made to matchup so closely. Was one perhaps modeled on the other? At a WAG, Persians had intrusions into India where they could have either borrowed or imposed their terms. I would guess it possible, once a moon-phase period was established in various cultures, that borrowing the names from other celestial bodies would be something that appealed to people who encountered other cultures with similar ways to track time. > [@](#): > > The moon has roughly 28 phases. To divide them into four is just arbitrary. I dunno. Arbitrary to mean “not imposed” makes sense. Obviously, not _everyone_ used a four-phase calendar. On the other hand, I do not believe that arbitrary to mean “capricious” is justified. I have not encountered a culture that did not recognize the Full and New moon phases in some manner and recognizing the clear half-way points between those events is not that hard to imagine. And it is a lot easier to describe those four phases–a complete circle, absent, and two divided by a straight line–than any of the other 24. (Is that a pared fingernail or a shaved fingernail phase, tonight?) ---
**Author:** ![stockton](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@stockton](https://boards.straightdope.com/u/stockton)\ **Post date:** [October 4, 2003, 2:38am UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/13 "2003-10-04T02:38:35Z")
There’s a great book about this subject, which address all the permutations of various “weeks” throughout history. Some were 10 days long, some were 3. It’s called “Waiting for the Weekend” Link: [http://www.amazon.com/exec/obidos/tg/detail/-/0140126635/103-5265463-5081401?v=glance](http://www.amazon.com/exec/obidos/tg/detail/-/0140126635/103-5265463-5081401?v=glance) Here’s a comparison of Saxon vs Roman gods, but I can’t vouch for the site. I always thought that the French “Friday” (Vendredi) was related to the fact that it was market day (vendre=vendor). Take it with a grain of salt, I only just googled it: [http://www.gwydir.demon.co.uk/jo/roman/daysweek.htm](http://www.gwydir.demon.co.uk/jo/roman/daysweek.htm) ---
**Author:** ![straightshooter](https://avatars.discourse-cdn.com/v4/letter/s/839c29/32.png) [@straightshooter](https://boards.straightdope.com/u/straightshooter)\ **Post date:** [February 21, 2013, 7:26pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/14 "2013-02-21T19:26:37Z")
When the first man, Adam, was created he knew about the seven day week. And that’s how it all started. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [February 21, 2013, 7:44pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/15 "2013-02-21T19:44:57Z")
> [@straightshooter](#): > > When the first man, Adam, was created he knew about the seven day week. And that’s how it all started. Reported as a Zombie; with religious, not factual, information being introduced into a 10 year old thread. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 21, 2013, 7:45pm UTC](https://boards.straightdope.com/t/where-did-the-7-day-weekly-cycle-originate/205087/16 "2013-02-21T19:45:57Z")
Since this thread is old and has been bumped without adding any factual information, I’m closing it. Colibri General Questions Moderator