360Days Formula

Is there a formula OR special add in to Excel that can calculate the TRUE
number of days between two dates. That is, a formula that takes into account
the 31st day of certain months and February 29 every four years? I find the
360days formula very helpful but I think users would get a lot more bang with
one that "truly" gave them the number of days between two given dates.
Please help. Thank you.

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http://www.microsoft.com/office/comm...lic.excel.misc

Microsoft uses a scheme called "Serial dates" to keep track of dates.
If you enter information in Excel-approved date format, you can
calculate the number of days between two dates as simply as =B1-A1
where A1 and B1 are dates. Do a search on time and date functions in
Help to find out how extensively this has been covered.