public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('dateOfBirth', DateType::class, ['label' => 'Your date of birth', 'data' => new \DateTime('1879-03-14', new \DateTimeZone('UTC')), 'widget' => 'single_text'])->add('submit', SubmitType::class, ['label' => 'Submit']);
}