12 can be divided by 2, 3, and 4. 13 is a prime number. There's a reason the number 12 comes back to often for these types of things. And the current calende

12 can be divided by 2, 3, and 4. 13 is a prime number. There's a reason the number 12 comes back to often for these types of things. And the current calender really isn't that much of a hassle.