Use jquery to trigger an event every XX amount of seconds. In this example we will trigger the click event on the "increment" ID.

jquery-trigger-event-every-x-seconds.js

/* WE ARE ASSUMING JQUERY IS LOADED AND USING jQuery instead of $ */
 
jQuery(document).ready(function($) {
  window.setInterval(function(){
  /// call your function here
  $('#increment').trigger('click');
}, 5000);
});
 
/* 
 * it may be better to use custom event attachment to properly sync 2 items though 
 * we are now assuming there are 2 buttons, a next and a previous button
*/
jQuery(document).ready(function($) {
  $('#next, #prev').on('click', function() {
      $('#increment').trigger('click');
    });
});