Why Seven Days in a Week?

The reason they adopted the number seven was that they observed seven celestial bodies — the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. ... The Babylonians divided their lunar months into seven-day weeks, with the final day of the week holding particular religious significance.

When did the 7 day week originate?

For centuries the Romans used a period of eight days in civil practice, but in 321 CE Emperor Constantine established the seven-day week in the Roman calendar and designated Sunday as the first day of the week.

Why are there 7 days in a week Hindu?

Celestial bodies are used to serialize the 7 days of the week. We can say this because, the days of the week have no relation with the movement of the planets in the night sky. ... In fact the Ancient Vedic system (as well as the Babylonian system) has a serializing logic to explain why “Sun”day is followed by “Mon”day.