I'm working with a spreadsheet that has a column for date of birth and of
course bumped up against the pre-1900 date issue. Some of the dates are
pre-1900 and some are post-1900. In another group of columns we want to
calculate ages of individuals over a number of years. Looking online, I
found John Walkenbach's XDate add-in at
http://j-walk.com/ss/excel/files/xdate.htm. I've downloaded it and installed
is as instructed. However, I can't figure out how to use it.

I'm using Excel 2003 on Windows XP.

Instructions say "You can type the functions manually, or use Excel's Paste
Function dialog box. To access the Paste Function dialog, click the Paste
Function button..." Is that the Insert Function button?

"or select Insert - Function. The XDate Functions are listed in the 'Date &
Time' Category. When a function is selected in the Paste Function dialog,
press F1 to read the online help." I've tone to Insert--Function. The
Insert Function window opens (not the Paste Function shown in his
screengrab). I choose the category Date&Time and select the function XDATE.
When I hit OK, I'm not sure how to use the Function Arguments window. For
the date 11/19/1893, opposite Y, M and D, I filled in 1893, 11, 19 and I
left the Fmt field blank. The function is shown as =XDATE(1893, 22, 19).
Although the cell contents display 11/19/1893, Excel is not seeing it as a
date, it seems to be still treated as text. Calculations based on the date
don't work and changing the cell to a different date format has no effect.

Can someone explain to me how to use the function properly in simple terms
as I'm only a basic user of Excel. Thank you.