Powers of 2 tend to be superior for more factors. Four weeks means we can easily reason about halves and quarters of months. Five weeks means we can only easily

Powers of 2 tend to be superior for more factors. Four weeks means we can easily reason about halves and quarters of months. Five weeks means we can only easily reason about fifths of months. For a similar reason, it might have been better if humanity had settled on a base 12 number system rather than base 10. We can only easily halve 10 while we can easily halve, third, and quarter 12. More factors means it's more intuitive to reason about common fractions of things. Earlier civilizations did use base 12, and we still have elements of that history in common use, like the special names for eleven and twelve in the English language and our 12 hour clocks. A common theory for the prevalence of myths about 6 fingered foreigners in the Bible is that these other cultures used base 12 numbers, and the only way people using base 10 could understand that was to assume that they must have 6 fingers to count with. Interestingly, you can actually use your fingers to count to 12, using the 3 segments on each of your 4 fingers rather than the 5 whole fingers.