This seems so impossible that I need to post it here with a request for
someone please to tell me why I'm wrong....

Excel 2003 can determine the number of days between two dates based on
a year of twelve months each having thirty days. And Excel 2003 can
determine the number of workdays between two dates. But, even with all
Microsoft optional analysis "tool-paks" installed, it appears that
Excel 2003 cannot calculate the number of days--not limited to work
days--between two dates based on an actual year, i.e., the number of
days in the actually involved months and year(s).

What I'm looking for is the functionality of Lotus 1-2-3's DAYS
function with a base of 1 (there are several optional bases for 1-2-3's
@DAYS, depending on the calendar assumptions you want to operate, and
"1" is actual number of days in the month/actual number of days in the
year).

Am I missing something??