如何使用utc时间戳symfony 4？

// 引入必要的类
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;

// 在控制器中使用UTC时间戳
class MyController extends AbstractController
{
    /**
     * @Route("/timestamp", methods={"GET"})
     */
    public function timestampAction(Request $request)
    {
        // 创建一个DateTime对象并设置时区为UTC
        $dateTime = new \DateTime('now', new \DateTimeZone('UTC'));

        // 获取UTC时间戳
        $timestamp = $dateTime->format('U');

        // 返回JSON响应
        return new JsonResponse(['timestamp' => $timestamp]);
    }
}