From Chips' site http://www.cpearson.com/excel/datedif.htm



=DATEDIF(Date1,Date2,Interval)

Date1 must be less than (earlier) or equal to Date2. Otherwise, =DATEDIF
will return a #NUM! error. If either Date1 or Date2 is not a date, =DATEDIF
will return a #VALUE! error.

By the way:
You do not need to format cells before entering dates. Just type the data
as, for example, 1/1/2002 and Excel recognizes a date.

--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"JohnH" wrote in message
...
I'm using Excel 2000 and trying to use the datedif function. I've formated
2
columns as date m/dd/yyyy and left the formula column general I'm entering
dates
A1: 1/1/2002
B1: 1/1/2005

I'm entering the formula in C1
=datedif(b1,a1,"M")

I'm looking for the nmber of months between 2 dates

I get #NUM! for a result.

Thanks
John