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Is Expression a Date Method

The Is Expression a Date method determines if an expression evaluates to a date that Siebel VB allows. It returns one of the following values:

• -1 (negative one). The expression is a date variable type or a string that Siebel VB can interpret as a date.
• 0 (zero). The expression is not a date variable type or a string that Siebel VB can interpret as a date.

For more information, see Variants.

Format

IsDate(expression)

The following table describes the arguments that you can use with this method.

Example

The following example adds a number to the current date value and determines if it is still a valid date. In this example, a valid date is in the range of January 1, 100, through December 31, 9999:

Sub Button_Click
   Dim curdatevalue
   Dim yrs
   Dim msgtext
   curdatevalue = DateValue(Date$)
   yrs = 20
   yrs = yrs * 365
   curdatevalue = curdatevalue + yrs
   If IsDate(curdatevalue) = -1 then
      msgtext = Format(CVDate(curdatevalue))
   Else
      "The date is not valid."
   End If
End Sub