The Seven-Day Week Has No Astronomical Basis
A week is a period of seven days. Unlike the day, month and year, it matches nothing in nature.
A week is a period of seven days. It is the only common unit of time with no astronomical basis: a day is one rotation, a month roughly a lunar cycle, a year one orbit, but seven days corresponds to nothing. The count probably comes from the seven classical planets visible to the eye, and the day names still record them — Saturn, Sun, Moon, and the Norse equivalents of Mars, Mercury, Jupiter and Venus. Attempts to change it, in revolutionary France and the Soviet Union, both failed.
- Seven days. *Next week.*
- A working period. *A four-day week.*
- Weekly. *A weekly meeting.*
- Weekend. *The weekend.*
- Old English — *wice*. *The source.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | week | A week. |
| Plural | weeks | Weeks. |
| Adjective | weekly | Weekly. |
| Compound | weekend | The weekend. |
| German | Woche | A week. |
- See you next week.Time.
- It matches nothing in nature.Fact.
- Day names record the planets.History.
Failed attempts to change the week
- Revolutionary France introduced a ten-day décade in 1793
- It was abandoned after twelve years
- The Soviet Union tried five- and six-day weeks from 1929
- Both aimed to break religious observance
- Both failed against a habit thousands of years old
Old English *wice*, of Germanic origin, related to German *Woche*.
Why are there seven days in a week?
Probably from the seven classical planets visible to the naked eye, whose names the days still carry.
Has anyone tried to change it?
Yes. Revolutionary France used a ten-day week and the Soviet Union tried five and six days. Both were abandoned.