On Thu, 11 Sep 2008 03:27:01 -0700, liztownsend
wrote:

Hope someone can help, I'm looking for a formula to work out date overlaps.
e.g.
If my key dates are 1/11/08 to 30/11/08
I want to auto calculate how many days the following overlap with my key dates
01/01/08 to 31/12/08
16/11/08 to 05/12/08
etc

thanks!


=SUMPRODUCT(--ISNUMBER(MATCH(ROW(INDIRECT(A5&":"&B5)),ROW(INDIRE CT(KeyDateStart&":"&KeyDateEnd)),0)))

Where your dates of interest are in A5 and B5
--ron