IsDate()

Function reference

Tests whether a string value is a valid date.

IsDate ( datavalue )

Data type: Boolean
Returns true if datavalue is a valid date and false if it is not.

Example1:
This expression returns true:
IsDate(‘Jan 1, 99’)

Example 2:
This expression returns false:
IsDate(‘Jan 32, 2005’)

Example 3:
This expression returns a day number or 0.
If [data] contains a valid date, the expression returns the number of the day, and otherwise returns 0:

If( IsDate( ‘[data]’ ) , DayNumber( Date(‘[data]’) , 0 )