AngularJS Example:

by Naghaveer R

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app>
 
  <div ng-controller="TodoCtrl">
    currect date:{{date}}
    <br>
    Renewal date:{{renewaldate}}
  </div>
</div>

JavaScript

function TodoCtrl($scope) {
 $scope.date="2016-08-30";
 var d=new Date($scope.date);
 var n=28; //number of days to add. 
 $scope.renewaldate=new Date(d.getFullYear(),d.getMonth(),d.getDate()+n);
}