title: Ionic 3 ion-datetime component and "ion-date-selected" event
body: <p>I'm new to AngularJS and got a problem with Ionic - I got a simple form, where I need to display a notification (Ionic's alert) if user selects particular date using <em>ion-datetime</em> component. In specification we can find <em>ion-cancel</em> event but there is nothing like <em>ion-date-selected</em>. </p>
  
  <p>Is there a way I could detect, that user selected a date? <em>ionChange</em> doesn't do a job either, because it's being fired multiple times. I know, I can subscribe to the model and check if has changed but maybe there is a better/simpler way?</p>