All solutions here doesn't really bind the model to the input because you will have to change back the dateAsString
to be saved as date
in your object (in the controller after the form will be submitted).
If you don't need the binding effect, but just to show it in the input,
a simple could be:
<input type="date" value="{{ item.date | date: 'yyyy-MM-dd' }}" id="item_date" />
Then, if you like, in the controller, you can save the edited date in this way:
$scope.item.date = new Date(document.getElementById('item_date').value).getTime();
be aware: in your controller, you have to declare your item
variable as $scope.item
in order for this to work.