title: Calculate timezone difference in jquery
body: <p>I have two timezone js string variable.</p>
  
  <pre><code>var User_Timezone = new Date(); // current user system timezone
  var User_Timezone= String(User_Timezone);
  
  //User_Timezone has value = "Fri Feb 21 2014 04:29:49 GMT-07:00 (US Mountain Standard Time)";
  
  var Admin_Timezone = "(GMT-06:00)-Central Time (US &amp; Canada)"; //always same
  </code></pre>
  
  <p>I want to calculate time difference(<strong>in minutes</strong>) between <code>Admin Timezone</code> &amp; <code>Client Timezone</code>. </p>
  
  <p><strong>Like:</strong></p>
  
  <pre><code>var TimezoneDifference = Admin_Timezone - User_Timezone; // difference in minutes
  </code></pre>
  
  <p>How should I do this in <strong>jQuery</strong>?</p>
  
  <p>Client timezone varies when any client access my page from different timezone but admin timezone is always same.</p>
  
  <p>I need only difference between admin and client timezone.</p>