Why is a dozen equal to 12?

Question:

Why is a dozen equal to 12?

why is a dozen equal to 12 and not some other number? Where and when did this tradition start? Any information would help.

Additional Details

1 week ago
Please read the whole question. I've already searched all the websites given by the first answerer, before I asked my question. Those website does not provide the answer.

Best Answer - Chosen by Asker: 1 week ago
Please read the whole question. I've already searched all the websites given by the first answerer, before I asked my question. Those website does not provide the answer.