Moon phases as time keeping are as old as any of the others (ie prehistoric) https://en.wikipedia.org/wiki/Lunar_phase https://en.wikipedia.org/wiki/Lunar_phas

Moon phases as time keeping are as old as any of the others (ie prehistoric) https://en.wikipedia.org/wiki/Lunar_phase https://en.wikipedia.org/wiki/Lunar_phase Does not line up perfectly with days, so different cultures handled that differently, but pretty much all cultures had something like a week.