public static function format_event_for_fullcalendar($event)
    {
        $bgColor = '#999'; //default
        $textColor = '#FFF'; //default
        $borderColor = '#555';

        $arr = array(
            'id'        => $event->ID,
            'title'     => $event->Title,
            'start'     => self::format_datetime_for_fullcalendar($event->StartDateTime),
            'end'       => self::format_datetime_for_fullcalendar($event->EndDateTime),
            'allDay'        => $event->isAllDay(),
            'className' => $event->ClassName,
            //event calendar
            'backgroundColor' => $bgColor,
            'textColor' => '#FFFFFF',
            'borderColor' => $borderColor,
        );
        return $arr;
    }