If n is invalid, the function returns an error. f (Optional) A date format string. If you do not include a value for f, the function uses the default date format MMM D, YYYY. k (Optional) A locale identifier string that conforms to the locale naming standards. If you do not include a value for k, or if k is invalid, the function uses the ambient locale.The function returns a value of 0 if any of the following conditions are true:Insufficient information is provided to determine a unique day since the epoch (that is, any information regarding the date is missing or incomplete.The following expressions are examples of using the Num2Date function:
Num2Date(Date2Num(“Mar 15, 2000″) - Date2Num(“98-03-15″, “YY-MM-DD”, “fr_CA”))