Why Do We Have a Seven Day Week?

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In this video:

Two of the earliest known civilizations to use a seven day week were the Babylonians and the Jews. The Babylonians marked time with lunar months and it is thought by many scholars that this is why they chose a seven day week (though direct evidence of this being why they did this is scant). That being said, each lunar month was made up of several different cycles—on the first day, the first visible crescent appeared; on approximately the seventh, the waxing half-moon could be seen; on approximately the fourteenth, the full moon; on approximately the twenty-first, the waning half-moon; and on approximately the twenty-eighth, the last visible crescent. As you can see, each notable cycle is made up of about seven days, hence, the seven-day week.

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[TodayIFoundOut]

Ready to learn more fun facts? Then check out this video and find out Why the Hottest Part of the Summer is Called the “Dog Days”:

[Cipher]

Extra Bonus Fact:

The days of the weeks got their names from a mixture of Norse and Roman mythology. They associated each day with one of the 7 naked-eye objects that can be seen moving in regular patterns throughout the sky: the sun, the moon, and 5 planets (mercury, venus, mars, jupiter, saturn). Sunday for the Sun, Monday for the Moon, Tuesday for Tyr (Tyr's day) which the Romans associated with Mars, Wednesday for Woden (Woden's day, Mercury to the Romans), Thursday for Thor (Thor's day, Jupiter to the Romans), Friday for Freya (Freya's day, Venus to the Romans), and Saturday for Saturn (Nordic tradition didn't associate a deity with this day, so the Romans got to name it).

[DanDart]

The Welsh and Celts used 8 day weeks too, their word for week reflects this.

[chrisg]

In a comment to a more recent of your vids "Why do we divide the day into seconds minutes and hours?", I suggest that our hour historically starts with logging and predicting the tidal cycle, and represents the time taken for 1/12 of the tidal range to be covered immediately before and after low water, a rule of thumb still in use today, and led to division of the conventional clock face into 12 hours. I think that this hour remains constant whatever the size of the tidal range is at any particular location over the month, whether during spring tides or neap tides. There is about a seven-day interval between springs and neaps, so tide could also have been a reason for the week as a unit of time. Each week would have had the same number of hours, even if that doesn't add up to an exact number of solar days.

[JakobFischer]

Germany is working hard to defend Sunday as a day of rest. Some europeans heldp but the phalanx of "sunday is a shopping day" is strong. Hope we succeed.

[gordonmccoy]

Although very interesting, you omitted the discussion of why the European calender starts on Monday, with Sat/Sun being on the far right and the American calender SPLITS the weekend with Sunday STARTING the week.... Where did we go wrong??? Gordon. .

[omidramak]

i love these shorter videos where you're standing up! concise, high energy and interesting! Thank you bro! god bless you! God loves us all! =-D <3

[skyscall]

Video idea: When did "ass" first become a bad word? (It used to mean "donkey" until about a hundred or so years ago.)

[skindreads]

Then The Beatles came along and repopularized the eight day week.

[thelonecabbage]

It never fails to amaze me how we humans cling to antiquated methods like this.

The most dangerous words in the human language : "We've always done it that way"

[filmdetective]

Since you're not moving much on your green screen, you really should put flags over your shoulders in the back ground, to counter the green spill on your skin, and it will give you a black surface for your glasses' branches to reflect (instead of green now, which is why we can see through your head). Cheers

[avlisk]

When I multiply 28 X 13, I get 364. Let's go to 13 months of 28 days, with Feb having 29 because that just seems right, and one day every 4 years being "Everybody Party Day" where all bets are off.

[MitchBurns]

Interesting, although you should have mentioned that the names of the week in English are based off of the Norse days of the week, like Thursday comes from the Norse Thor's Day.

[wolftalk]

did anyone else notice that his glasses were keyed out along with his green screen?

[davidrobinson]

Assuming that moon cycles were the reason for the number of days, why was a seven day week chosen instead of a 14 day week? There is nothing obvious about dividing the month into quarters.

[gammondog]

0:35 Quarter moon! Not half. By the way, half moon refers to full moon because it's halfway into the lunar cycle.

[juanc.tagaytay]

The seven day weekly cycle has no reference other than that on the account of creation found in the Bible. It is no coincidence. The weekly cycle serves as a reminder to man that there is a Creator and that man is a created being. That is why the 4th commandment which is about the Sabbath starts with the word "remember." The only commandment that starts differently. Sadly, only a very few people know about this. This fact proves the validity of the Bible and also of the existence of the Almighty.

[Philson]

Watching these videos are like going to school again. Subscribed!

[HistoricaHungarica]

Should have throw in the bonus fact that in roman times 1st of january wasn't the new years eve. Since it was 1st of march.
And that there was february 30 in those 10 and 5 day calendars.
But good video.

[mattthie]

Why is it that the video drags significantly behind the audio when watched on a mobile device? I've notice this for several weeks now--it starts out in sync, but after the opening Today I Found Out intro it starts lagging more and more as the video progresses.