I have tried this function but am having trouble with it returning the right
value. I have an end-date of 1/20/2010 (in cell F16) and a start-date of
2/11/2009 (in cell E16). I'm trying to calculate how many automatic monthly
transfers there will be on the 20th of each month but the function is
returning a value of 11 when it should return a value of 12. The first
transfer will be 2/20/2009 and the last transfer will be 1/20/2010…a total of
12 transfers.

"David Biddulph" wrote:

I hope that Dec 2008 - Jan 2006 is 35, rather than 23. :-)

An alternative to DATEDIF would be
=MONTH(A1)-MONTH(B1)+12*(YEAR(A1)-YEAR(B1))
Note that if you have different dates within the start and end months,
you'll get different results from the 2 formulae.
End of Jan to beginning of Feb gives a 1 month difference with the original
=MONTH(A1)-MONTH(B1) and with my extension thereto, but DATEDIF counts
completed months (with various questions when months are of unequal length).
--
David Biddulph

"Ron Rosenfeld" wrote in message
...
On Sun, 30 Dec 2007 18:37:01 -0800, Mike
wrote:

=MONTH(A1)-MONTH(B1)

That works when the two months are in the same year, but what if they are
in
different years? For example January 2008-September 2007 = -8, but should
equal 4. Or December 2008-January 2006 = 11, but should equal 23.

Use the undocumented DATEDIF function:

=DATEDIF(B1,A1,"m")

(The first date must be the earlier date).


See http://www.cpearson.com/Excel/datedif.aspx for documentation.

--ron