The week being Babylonian is uncertain. Their monthly feast days were roughly seven days apart, yes, but their months were lunar months, not even multiples of s

The week being Babylonian is uncertain. Their monthly feast days were roughly seven days apart, yes, but their months were lunar months, not even multiples of seven (https://en.m.wikipedia.org/wiki/Babylonian_calendar https://en.m.wikipedia.org/wiki/Babylonian_calendar). Judaism still seems like the most likely origin, though the Babylonian Captivity could have played some part.