Change AngularJS input[date] programmatically

I'm trying to assing an input[date] control an initial value in the controller.

From AngularJS input[date] documentation,

The model must always be a Date object, otherwise Angular will throw an error.

They provide a working example of how to init an input[date] in the controller (Pasted a simplified version), that works on Plunker.

<script>
   angular.module('dateInputExample', [])
     .controller('DateController', ['$scope', function($scope) {
       $scope.value = new Date(2013, 9, 22);
     }]);
</script>
<form name="myForm" ng-controller="DateController as dateCtrl">
   <input type="date" id="exampleInput" name="input" ng-model="value" />
</form>

When I do the same in my application I always get the following message:

The specified value 'Sun Nov 09 2014 00:00:00 GMT+0100 (CET)' does not conform to the required format, 'yyyy-MM-dd'

and the control is not initialized. Seems that it is expecting a string in ISO format and not a valid Date Object.

In Set default value of HTML5 date input field with angularJS an alternate method is proposed:

<input type="date" ng-model="date" value="{{date}}">
...
$scope.date = $filter("date")(Date.now(), 'yyyy-MM-dd');

It just assigns a "yyy-MM-dd" string to the model. According to the docs this should throw an error, since a string is not a valid Date Object, but this second method works for me, but funny, does not work if you use it in the modified original Plunker, adapted to use this method.

1. What can be messing my input[dates] so I can't set the value in the controller as expected?
2. Why is the alternate method working for me (and others) but not working in the simple demo provided?

Here are some excerpts from my code where the input[type] is created and where it is assigned the initial value:

index.html

<input type="date" name="input", ng-model="value" />

Controller

.controller("UploadsCtrl",["$scope","$filter", function($scope, $filter) {
    // $scope.value = new Date(2013, 22, 9); // Not working
    $scope.value = "2015-10-10"; // Working!!!!
    ...