Set source and input format for DateValidator
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:DateValidator source="{birthday}" property="text" inputFormat="mm/dd/yyyy" allowedFormatChars="/" trigger="{submitButton}" triggerEvent="click" /> <mx:Text text="Enter your birth date:" /> <mx:TextInput id="birthday" /> <mx:Button label="Submit" id="submitButton" /> </mx:Application>