I am in need of a function that will return a quarter based upon the existing date. For example, if todays current date is 3/31/12 and I am working with a future date of 3/31/16 I need a function that would return quarter 16 (being 16 quarters from my "current date"), and further any date between 1/1/18 and 3/31/18 would return a quarter 24 (being 24 quarters form my "current date"). I need this to be accurate through 40 quarters. Please help.
As a futher example:
Current date=3/31/12
Dates 4/1/12-6/30/12=Quarter 1
Dates 7/1/12-9/30/12=Quarter 2
Dates 10/1/12-12/31/12=Quarter 3
Dates 1/1/13-3/31/13=Quarter 4
Dates 4/30/13-6/30/13=Quarter 5
Dates 7/1/13-9/30/13=Quarter 6

and so on

It needs to work that so anytime I change the current date the quarters follow suit.

Thank you