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This will produce last day number (dd) of current month
=Left(CDate("01/" & (Mid(Date(),4,2)+1) & "/" & Year(Date()))-1,2)
This produces last day of current month (dd/mm/yyyy)
=Left(CDate("01/" & (Mid(Date(),4,2)+1) & "/" & Year(Date()))-1,2) & "/" & Mid(Date(),4)
Smed