shipulina

{
            xtype: 'datefield',
            fieldLabel: _('note_date'),
            name: 'date',
            format: 'Y-m-d',
            id: config.id + '-date',
            anchor: '99%',
}

public function beforeOutput()
    {
        if(!empty($this->object->date)) {
            $date = new DateTime($this->object->date);
            $this->object->date = $date->format('Y-m-d');
        }
    }