FullCalendar无法在cakephp3.x中显示事件

Question

我知道这个问题已经被很多人提出，但是我仍然没有找到解决问题的答案

TutorsController：

public function index()
{
    $this->loadModel('Events');
        $events = $this->Events->find('all');
        foreach ($events as $event) {
            $data[] = array(
                'id' => $event->id,
                'title' => $event->title,
                'start' => $event->start->format('Y-m-d H:i:s'),
                'end' => $event->end->format('Y-m-d H:i:s'),
            );
        }
        $this->set('json', json_encode($data, JSON_HEX_QUOT | JSON_HEX_TAG));
        $this->set('_serialize', 'data');
}

js文件：

$(document).ready(function(){
    var calendar = $('#calendar').fullCalendar({
        header:{
            left: 'prev,next today',
            center: 'title',
            right: 'agendaWeek,agendaDay'
        },
        defaultView: 'agendaWeek',
        editable: true,
        selectable: true,
        allDaySlot: false,
        height : function() {
            return $(window).height()*0.8;
        },
        events: "http://localhost/jp_matching/tutor/tutors",
}

请帮助我！