Mythologies behind Seven-day Week The Origin A week is a unit of time equal to seven days. The seven-day week stems from ancient Mesopotamia around 600 BCE. The earliest evidence of an astrological significance of a seven-day period is a decree of king Sargon of Akkad around 2300 BC. Akkadians venerated the number seven, and the key celestial bodies visible to the naked eye numbered seven (the Sun, the Moon and the five closest planets). Some ancient and traditional cultures had different week lengths, including ten days in Egypt and an eight-day week for ancient Romans , who later switched to a seven-day week.Historically, indigenous Indian timekeeping relied on a luni-solar system divided by lunar phases (tithis), months, and fortnights (pakshas). The adoption of the seven-day week (Vara) occurred alongside Indo-Greek and Mesopotamian cultural exchanges, eventually solidifying in Sanskrit astronomical texts like the Surya Siddhanta and Pancasiddhantika between the 1st and...