title: disply the current week start and end date
body: <p>I want to display the Current week in <code>UINavigationBar</code> and then click on Next or Previous button to display the Previous week or Next week</p>
  
  <p>Example:</p>
  
  <pre>
  July 22 - July 28
  July 29 - Auguest 4
  </pre>