7 day week ?

[gmc2002]

Why do we have a seven day week ?
Are there any other lengths in other cultures
Do they all have the concept of the week ?
Who started it?
Why seven days ?

[gmc2002]

Ok...
But why not two weeks of 14 days per lunar month, or seven weeks of 4 days ?.

[stoo_pid]

No-one really knows where it came from but it is known to have been around at least since ancient Babylonian times. The most popular theory is that they knew about 5 planets of our solar system plus of course, the Sun & the Moon. Each was linked to a God. To cut a long story short they settled on a 7-day week. There are various other theories but, as an atheist, my favourite is the one that says its because God (having done all his work in 6 days followed by a well-earned day off) said so!

[Quizmonster]

It's lunar, as Allen says above, and tidal in origin, Gmc. Nearly all calendars were started by peoples living in fertile river valleys, such as the Tigris and Euphrates, whose estuaries are tidal.  Between new moon and full moon, tides at first decrease and then increase in height, influenced by the moon's pull, and this sequence repeats round to new moon again.  That is, there are four clear sections of about seven days which more or less fit each lunar month and the early calendar-makers were aware of this.

[montyy]

it says in the bible that...

jus kiddin! im not a bible-basher! lol

hu knows..

[CTC]

I'm not a Bible-basher either, but there is some validity in referring to Genesis 1&2 for an answer. It makes logical sense compared to other answers you could receive.