The old Babylonian system used a number system based on 60, traces of which we still see in 360 degrees or 60 minutes.

Wikipedia has this to say about 60:

"A common theory is that 60, a superior highly composite number (the previous and next in the series being 12 and 120), was chosen due to its prime factorization: 2×2×3×5, which makes it divisible by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30. In fact, it is the smallest integer divisible by all integers from 1 to 6. Integers and fractions were represented identically — a radix point was not written but rather made clear by context."

Which also tells us something about 12. 2x2x3=12 (prime factorization). Divisible by more numbers than 10. Basically it is an interesting number to play around with, which creates room for creating symbolic meanings.

OP, found a previous post on this

Why do we have a dozen? Why do we need another word for 12 items?

edit: here's another discussion on 'dozen':

What was so significant about a two-week period that it got its own English word, "fortnight"?

As a further question, are the origins of the phrase 'a baker's dozen' to mean 13 from baker's actually putting a spare in a set?

as the name implies and my mother told me, or rather is it elsewhere?

Did everybody miss that douze is 12 in French. And douzaine is dozen.

Note that french has dizaine as well for tens.

So I would say dozen comes from the importance of the number 12 and etymologically comes from French.