title: Angular watcher does not work when listener is the Date() function
body: <p>I know I am asking a question that has an extremely simple answer (I am new to angular and it did take a lot of courage to ask this here ;). I have a directive that displays the time like this:</p>
  
  <pre><code>Application.Directives
  .directive('theClock', function(){
      return {
          retrict: 'EA',
          templateUrl: 'partials/partial.clock.html',
          link: function(scope, elem, attrs) {
  
              scope.dTime = Date();
              scope.$watch( function(scp){ return Date(); }, function(newVal){ 
  
                      scope.dTime = newVal;
                  }
              );
          }
      };
  });
  </code></pre>
  
  <p>I expect that the time would update every $digest cycle but it does not. I know that  using <code>setInterval</code> ot <code>$timeout</code> is another way to do this, but I dont really want a clock, I want to understand why the update does not happen. BTW I did call <code>$apply()</code> after checking for <code>$$phase</code> - did not help</p>
  
  <p>Thank you.</p>