Most of our major divisions of time are based on some natural event.

A year is one orbit of the Earth around the Sun.

A month is one orbit of the Moon around the Earth,

and a day is a rotation of the Earth about its access.

However, one of the most commonly used units of time

has no natural analog whatsoever.

Learn more about why there are seven days in a week

and where the names for the days of the week come from on this

episode of Everything Everywhere Daily. Book your ticket to happiness with Sun Express Airlines. I've done many episodes on how our calendar came to be.

I've talked about how the Gregorian calendar fix the Julian calendar.

I've done episodes on why January 1st is the beginning of the year. I've talked about the Roman origin of where our months come from, and I've also got into way too much detail

talking about why we started numbering years the way we do.

So I kind of have a thing about time and calendars.

Nonetheless, despite all the episodes I've done on this

subject, there's one thing I haven't touched yet. The week. A week has seven days,

yet there's nothing in nature that's on a seven-day cycle.

Unlike years, months, and days, a week is an entirely arbitrary unit of time.

So why are there seven days in a week, not five or nine or something else.

I should note that there were other ancient civilizations that did have a different number of days in their

week. The Egyptians had a ten-day week. The Etruscan's had an 8-day week which was adopted by the early Romans.

Likewise, the Celts had an 8-day week, but a Celtic fortnight, which is where the term originates, was actually 15 days.

One of the problems with making a calendar is that none of the natural units of time are

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