title: Date validation using angular material date picker
body: <p>I am trying to validate dates using the material date picker.  Specifically what I am trying to validate is when the user types 'abc' into a date field I would like to show them 'please enter a valid date'.  I would like to be able to do that on keystrokes so when they enter 'a' and 'ab' and 'abc' they get the same  error.</p>
  
  <p>The problem is the date picker appears to not set the model value and its errors until the value is able to parse to a date.  I know this because the form control is not dirty and it still has an error of required when typing 'abc'.</p>
  
  <p>Can this be done?</p>