It is not working. What format do my cells need to be in?

"Mike H" wrote:

Try,

=DATEDIF(A1,B1,"d")

Mike

"Justin" wrote:

I just want to be able to count days between two dates. I am using excel 2003.

example
a1 12/5/1999 b1 03/04/2007
if i want the number of days between a1 and b1 in c1, what should the
formula read? What format should each of the cells be in?