It is funny how the whole world believes that the 7 day week is a western concept!
7 day week is not a concept borrowed from Romans as it is generally believed.
The 7 day week is not really based on western calendar. Firstly, lets look at how classic predictions ( Jyothisha Shastra ) of the Vedas for answers to these questions:
Why do we have only 7 days in a week? Why can't we have 8 or 9? What is an hour? Why do we have only 24 hours in a day? Why can't we have 30 or 40 units and call it an hour?
Ancient Indians were so well versed that they often used 4 to 5 different units of time. If you ask your Indian grand mother, she might have told you that during her days, people measured time in a weird unit called ghati/ghadiya (1 ghati = 24 minutes).
1 day is the time lapsed between two sunrises. Sandhi in sanskrit means knot or junction and hence the junction points are named as pratah sandhya(Early morning) and sayam sandhya (Evening) which divide the standard day
