--Suppose you have your data arranged in the below format. Please note that
the months displayed in cell C1 is entered in excel date formats
formatted to display as mmm-yy

Col A Col B Col C
Date In Date Out Jan-09
9-Jan-09 16-Mar-09 23

--The formula to be applied in cell C2 is given below. Copy the cells to the
right as required

=MAX(0,MIN($B2,DATE(YEAR(C$1),MONTH(C$1)+1,1))-MAX($A2+1,DATE(YEAR(C$1),MONTH(C$1),1)))

--
If this post helps click Yes
---------------
Jacob Skaria


"Danny" wrote:

Hi there, I'm not quite sure if this can be done or not, but any help/advice
would be really appreciated.

I would like to work out capacity (in days) of a certain month from
different start dates and end dates. As an example below, I would like to
display for each record how many days in January are being used; so row 2
should display 26 days in January, row 3 the full 31 days in January, and row
4 should be 2 days in January.

A B
1 start end
2 14th Nov 08 26th Jan 09
3 16th Oct 08 04 Feb 09
4 30th Jan 09 10 Feb 09

Is there a formula to display this?
thanks,
Danny.