IsDate Function Incorrectly Identifies Some Expressions

CAUSE

This problem occurs if the expression that is being evaluated by the IsDate function uses a date format that is not normally recognized as valid by Microsoft Excel. The following date formats are not recognized.

   Format           Example
   -----------------------------
   year-day-month   2002, 5 July
   month-year-day   July, 2002 5
   day-year-month   5, 2002 July
				

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. For example, if you run the following macro

   Sub TestIsDateFunction()
       MyDate = "2002, 5 July"   'an invalid date expression
       MsgBox IsDate(MyDate)     'is it a date?
   End Sub
				

the message box displays True instead of False even though the date is not valid in Microsoft Excel.

   Sub ConvertDate()
       MyDate = "2002, 5 July"   'an invalid date expression
       CnDate = CDate(MyDate)    'convert MyDate into a valid date
       MsgBox CnDate             'display the new, valid date
   End Sub
				

   Format           Example
   -----------------------------
   month-day-year   July 5, 2002
   day-month-year   5 July, 2002
   year-month-day   2002, July 5