Why 60?

My guess is that 60 has something to do with deep breathing in meditation.

Others have pointed out that 60 is divisible by many smaller numbers. How easy it is to get to sixty when you're dealing with a circle. The number of days in a year.

Anyway, we know it's been useful for further cutting up time.

And with delineated time, people could predict the movements of heavenly bodies.

Lest you think it all came from Sumerians.