shows your age, i've never even heard of them
now growing up, there was what we called a 13th month
most places would pay out every 4th week, and most people would budget their months according to those 4 weeks
4 times 12 is 48 of course, but 365 divided by 7 is 52
52-48 is 4 weeks that didnt get paid out yet, and thats what they would call the 13th month
its a great lil bonus, and can be easily turned around by us normal people
lets say your mortgage is 1200 dollars, instead of paying 1200 per month, you put 300 per week in an account you then pay your monthly mortgage payment out of it
in one year you put in 15600, but only pay out 14400, leaving exactly one extra monthly payment with can than go to principle (or carparts)
im guessing you've never seen "office space"?
on a side note, there are several countries in europe who no longer use any cash smaller than 5 cents
if you are paying with cash and buy something which is, say, 9.07, it will automatically drop to 9.05, but if it is 9.08 it will jump up to 9.10
now they question becomes, where do THOSE pennies go?