Edit in JSFiddle

$(function () {
    $("#date").datepicker({
                            dateFormat: 'yy-mm-dd'
                        });
});

angular.module("date", [])
    .directive("datepicker", function () {
    return {
        restrict: "A",
        link: function (scope, el, attr) {
            el.datepicker({
                            dateFormat: 'yy-mm-dd'
                        });
        }
    };
})
    .controller("dateCtrl", function ($scope) {
});

<div ng-app="date">
<div ng-controller="dateCtrl">
  <!-- jq -->
  jq:<input type="text" id="date" name="date" ng-model="date">
  <span>{{date}}</span><br>
  
  <!-- ng -->
    ng:<input type="text" datepicker ng-model="date2" />
  <span>{{date2}}</span>
</div>
</div>

</style> 
<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/themes/smoothness/jquery-ui.min.css" rel="stylesheet" type="text/css" /> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script> 
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/jquery-ui.min.js"></script> 
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.5/angular.min.js"></script> 
<style>