Angular js order by date dd-mm-yyyy - angularjs

Question

I want to order date. But doesn't work correctly. Date format is dd-mm-yyyy. Just order dd format doesn't check mm and yyyy. How can I solve?
JS
$scope.sortOptions = [
{
name:'Date desc',
sortCategory:'-anndate'
},
{
name:'Date asc',
sortCategory:'anndate'
}
];
HTML
<select ng-model="selectedSortType" class="custom-select">
<option value="" selected="">Select type</option>
<option value='{{opt.sortCategory}}' ng-repeat="opt in sortOptions track by $index">{{opt.name}}</option>
</select>
<div ng-repeat="i in res| orderBy:selectedSortType">
<div>{{i.anndate}}</div>
</div>

Answer 1

var app = angular.module('app', [])
.controller('appController', appController);
appController.$inject = ['$scope', '$window'];
function appController($scope, $window) {
$scope.title = "date sorting example";
$scope.sortOptions = [{
name: 'Date desc',
sortCategory: '2018-07-15 '
},
{
name: 'Date desc',
sortCategory: '2018-07-12 '
},
{
name: 'Date asc',
sortCategory: '2018-07-13'
}
];
};
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="app" ng-controller="appController">
<p>Ascending Order</p>
<div ng-repeat="i in sortOptions | orderBy:'sortCategory'">
<p>{{i.sortCategory}}</p>
</div>
<select ng-model="selectedSortType" class="custom-select">
<option value="" selected="">Select type</option>
<option value='{{opt.sortCategory}}' ng-repeat="opt in sortOptions | orderBy:'sortCategory'">{{opt.sortCategory}}</option>
</select>
<p>Descending Order</p>
<div ng-repeat="i in sortOptions | orderBy:'-sortCategory'">
<p>{{i.sortCategory}}</p>
</div>
<select ng-model="selectedSortType" class="custom-select">
<option value="" selected="">Select type</option>
<option value='{{opt.sortCategory}}' ng-repeat="opt in sortOptions | orderBy:'-sortCategory'">{{opt.sortCategory}}</option>
</select>
</div>

Answer 2

Try this..
Since the date in res object is in string format the filter is applying on dd value.
For entire date filter you need to convert the anndate to Date() object
Place the following code in the line below assigning res value in controller
angular.forEach($scope.res,function(item){ item.anndate = new Date(item.anndate); });
Then in html replace with below line
<select ng-model="selectedSortType" class="custom-select">
<option value="" selected="">Select type</option>
<option value='{{opt.sortCategory}}' ng-repeat="opt in sortOptions track by $index">{{opt.name}}</option>
</select>
<div ng-repeat="i in res| orderBy:selectedSortType">
<div>{{i.anndate| date : 'dd/MM/yyyy'}}</div>
</div>