Perhaps something like this:
For a list of dates in A1:A500
C1: =INDEX($A$1:$A$500,INT(RAND()*500))
Copy C1 down through C25
format those cells as dates
That will choose 25 random dates from the range A1:A500
To check if you have any duplicate dates listed....
D1: =SUMPRODUCT((C1:C25<>"")/COUNTIF(C1:C25,C1:C25&""))
If that formula returns anything less than 25...there are duplicates..recalc.
Note: the RAND function is volatile and generates new numbers every time the
workbook recalculates. Consequently, the list of dates will also keep
changing.
If you would like to deal with a static set of dates, create a Pivot Table
based on the random date list. Since Pivot Tables create an internal cache of
the source data, the Pivot Table list will not change even if the random date
list keeps changing. Anytime you want to use a new list of random dates,
just refresh the Pivot Table data
Is that something you can work with?
***********
Regards,
Ron
XL2002, WinXP