I am trying to validate a date entered into a text box. There is an input mask on the textbox which forces input of xx/xx/xxxx. I am trying to use a regular expression valid
You can use DateTime.TryParseExact:
DateTime dt; bool isValid = DateTime.TryParseExact( "08/30/2009", "MM/dd/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out dt);