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.

Argument	Description
expression	Any valid expression.

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