No, there is not auto-unpublishing option. We suggest to edit models/Pois_model.php and controllers/Pois.php to return to app only not-expired events. So, open models/Pois.php and add this method 

public function published_not_expired_pois()
	{
		return $this->db->query('SELECT * FROM `pois` WHERE `status` = 2 AND `end_date_time` > NOW() ORDER BY `title` ASC');
	}
After this, edit the controllers/pois.php file and replace the index_son method (line 49) to 
function index_json()
	{
		$this->data['data']['events'] = $this->pois_model->published_not_expired_pois()->result();
		
		$this->_json_out('json/api', $this->data);
	}