The seven-day week is not related to the number of stars in the Big Dipper. The origin of the seven-day week is much more complex and likely based on a combination of factors like:

* Lunar cycles: Early civilizations observed the moon's phases, which roughly cycle every 29.5 days. A week might have been a way to break down the lunar month into smaller units.

* Astrology: Some ancient cultures, like the Babylonians, had a strong connection to astrology and used the seven visible planets (Mercury, Venus, Mars, Jupiter, Saturn, the Sun, and the Moon) to define their week.

* Religious practices: In some religions, like Judaism and Christianity, the seven-day week is linked to the biblical story of creation, where God created the world in six days and rested on the seventh.

While the Big Dipper is a prominent constellation, its stars have no connection to the establishment of the seven-day week.