Devise\Calendar\PageVersionSource::updatePageVersion PHP Method

    public function updatePageVersion($id, $start, $end, $published)
    {
        if (!$published) {
            $start = null;
            $end = null;
        }
        $pageVersion = $this->PageVersion->with('page')->findOrFail($id);
        $pageVersion->starts_at = $start !== '' ? $start : null;
        $pageVersion->ends_at = $end !== '' ? $end : null;
        $pageVersion->save();
        return $this->fetchEvent($pageVersion);
    }

 /**
  * Requests that a page version event's start and end times
  * be updated
  *
  * @param  int   $id
  * @param  array $input
  * @return Response
  */
 public function requestPageVersionEventUpdate($id, $input)
 {
     $start = array_get($input, 'start');
     $end = array_get($input, 'end');
     $published = array_get($input, 'published', false);
     $event = $this->PageVersionSource->updatePageVersion($id, $start, $end, $published);
     return $this->Response->json($event);
 }