/**
  * Parse timing info
  * @param object $a_ref_id
  * @param object $a_parent_id
  * @param object $timing
  * @return 
  */
 protected function parseTiming($a_ref_id, $a_parent_id, $timing)
 {
     $type = (string) $timing['Type'];
     $visible = (string) $timing['Visible'];
     $changeable = (string) $timing['Changeable'];
     include_once './Services/Object/classes/class.ilObjectActivation.php';
     $crs_item = new ilObjectActivation();
     $crs_item->setTimingType($type);
     $crs_item->toggleVisible((bool) $visible);
     $crs_item->toggleChangeable((bool) $changeable);
     foreach ($timing->children() as $sub) {
         switch ((string) $sub->getName()) {
             case 'Start':
                 $dt = new ilDateTime((string) $sub, IL_CAL_DATETIME, ilTimeZone::UTC);
                 $crs_item->setTimingStart($dt->get(IL_CAL_UNIX));
                 break;
             case 'End':
                 $dt = new ilDateTime((string) $sub, IL_CAL_DATETIME, ilTimeZone::UTC);
                 $crs_item->setTimingEnd($dt->get(IL_CAL_UNIX));
                 break;
             case 'SuggestionStart':
                 $dt = new ilDateTime((string) $sub, IL_CAL_DATETIME, ilTimeZone::UTC);
                 $crs_item->setSuggestionStart($dt->get(IL_CAL_UNIX));
                 break;
             case 'SuggestionEnd':
                 $dt = new ilDateTime((string) $sub, IL_CAL_DATETIME, ilTimeZone::UTC);
                 $crs_item->setSuggestionEnd($dt->get(IL_CAL_UNIX));
                 break;
             case 'EarliestStart':
                 $dt = new ilDateTime((string) $sub, IL_CAL_DATETIME, ilTimeZone::UTC);
                 $crs_item->setEarliestStart($dt->get(IL_CAL_UNIX));
                 break;
             case 'LatestEnd':
                 $dt = new ilDateTime((string) $sub, IL_CAL_DATETIME, ilTimeZone::UTC);
                 $crs_item->setLatestEnd($dt->get(IL_CAL_UNIX));
                 break;
         }
     }
     if ($crs_item->getTimingStart()) {
         $crs_item->update($a_ref_id, $a_parent_id);
     }
 }