I have Excel 2k, and this is the entry in Help for DATEDIF:
" ...
DATEDIF
See also
Calculates the number of days, months, or years between two dates. This
function is provided for compatibility with Lotus 1-2-3.
Syntax
DATEDIF(start_date,end_date,unit)
Start_date is a date that represents the first, or starting, date of
the period. Dates may be entered as text strings within quotation marks
(for example, "2001/1/30"), as serial numbers (for example, 36921,
which represents January 30, 2001, if you're using the 1900 date
system), or as the results of other formulas or functions (for example,
DATEVALUE("2001/1/30")). For more information about date serial
numbers, see NOW.
End_date is a date that represents the last, or ending, date of the
period.
Unit is the type of information you want returned.
Unit Returns
"Y" The number of complete years in the period.
"M" The number of complete months in the period.
"D" The number of days in the period.
"MD" The difference between the days in start_date and end_date. The
months and years of the dates are ignored.
"YM" The difference between the months in start_date and end_date. The
days and years of the dates are ignored.
"YD" The difference between the days of start_date and end_date. The
years of the dates are ignored.
Remarks
Microsoft Excel stores dates as sequential serial numbers so that it
can perform calculations on them. Excel stores January 1, 1900, as
serial number 1 if your workbook uses the 1900 date system. If your
workbook uses the 1904 date system, Excel stores January 1, 1904, as
serial number 0 (January 2, 1904, is serial number 1). For example, in
the 1900 date system, Excel stores January 1, 1998, as serial number
35796 because it is 35,795 days after January 1, 1900. Learn more about
how Microsoft Excel stores dates and times.
Excel for Windows and Excel for the Macintosh use different date
systems as their default. For more information, see NOW.
Examples
DATEDIF("2001/1/1","2003/1/1","Y") equals 2, or two complete years in
the period.
DATEDIF("2001/6/1","2002/8/15","D") equals 440, or 440 days between
June 1, 2001, and August 15, 2002.
DATEDIF("2001/6/1","2002/8/15","YD") equals 75, or 75 days between June
1 and August 15, ignoring the years of the dates.
DATEDIF("2001/6/1","2002/8/15","MD") equals 14, or the difference
between 1 and 15 - the day of start_date and the day of end_date
- ignoring the months and the years of the dates.
.... "
I understand this was removed from later versions of Excel, but feel
free to read the above !!
Hope this helps.
Pete
