The Origins and Evolution of the Seven-Day Week
TLDR The seven-day week is an arbitrary unit of time with no natural basis, but it was introduced by the Babylonians and later adopted by various civilizations including Persia, Judea, Greece, India, China, and Rome. Emperor Constantine made the seven-day week official in 321, and the days of the week in different languages have origins in planets, Roman and Norse gods. The concept of a weekend and the definition of the first day of the week vary across countries, and while there are no international standards for the week, the agreement on days, months, and years remains consistent.
Timestamped Summary
00:00
The week, unlike other units of time, is an arbitrary unit with no natural analog, and the reason for its seven-day length is unknown.
01:59
The Babylonians introduced the seven-day week and associated each day with one of the seven planets, which ultimately became the standard.
03:48
The adoption of the seven-day week spread to Persia, Judea, Greece, India, China, and Rome, and was later made official by Emperor Constantine in 321.
05:23
The days of the week in Romance languages correspond more closely to the names of the planets than in English or Germanic languages.
07:17
The days of the week in English have origins in Roman and Norse gods, and the concept of a weekend is a relatively modern invention.
09:08
The concept of a weekend as two consecutive days off from work is relatively new, with different countries having different days off and different definitions of a weekend, and there is disagreement on whether Sunday or Monday is the first day of the week.
10:54
The concept of a week lacks international standards, but as long as everyone agrees on days, months, and years, the specific week doesn't matter much.