I decided to work through it. Looks like this will work:

=SUMPRODUCT((MAX(($A$1:$A$8)*($B$1:$B$8=$B10))))-SUMPRODUCT(SMALL(($A$1:$A$8)*($B$1:$B$8=$B10),COUN TIF($B$1:$B$8,"<"&$B10)+1))

But a couple others came up with others that will probably work.

HTH,

Conan






"Conan Kelly" wrote in message
...
DoooWhat,

Using your example, I would put a list of all possible years below the
data (you could put it along side or on a different sheet if you want).
So in cells B10:B12, I would have 2008, 2009, & 2010.

Then in A10, I would enter this formula:

=sumproduct((max($A$1:$A$8))*($B$1:$B$8=$B10))-sumproduct((min($A$1:$A$8))*($B$1:$B$8=$B10))

Then copy that formula down to A11 & A12. Format A10:A12 as a number
instead of a date.

(I did not test this formula...I'm taking an educated guess and I hope my
syntax is correct)

HTH,

Conan




"DoooWhat" wrote in message
...
I need to find the difference between the maximum and minimum values
of several different groups. I have the following data:

A B
1 1/1/2008 2008
2 1/15/2008 2008
3 1/31/2008 2008
4 4/1/2009 2009
5 4/21/2009 2009
6 7/1/2010 2010
7 7/14/2010 2010
8 7/26/2010 2010

I want to know what the range of dates is for each year. For example,
in analyzing 2008, I want a formula that will produce a value of 30.
For 2009, it should be 20. For 2010, it should be 25.

My list will be very large and will not necessarily be in the right
order. I tried to use a combination of "min", "max", and
"sumproduct", but I couldn't get it to work. This was what I came up
with.

=SUMPRODUCT((A1:A500=MIN(A1:A500))*(A1:A500<=MAX( A1:A500))*(B1:B500="2008"))

Any help would be very much appreciated.

Kevin