datetimepicker error submitting form

Question

I'm trying to use a jquery datetimepicker.

And I have some trouble when I submit the form:

This value is not valid. : Unable to reverse value for property path "debut": Date parsing failed: U_PARSE_ERROR

Here is my form:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('debut', 'datetime', array(
            'widget' => 'single_text',
            'label' => 'Debut',
            'html5' => false,
            'format' => 'dd/MM/yyyy H:m'
        ))
  //...

And the javascript is:

<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-datetimepicker/2.5.4/build/jquery.datetimepicker.full.min.js"></script>

<script>

    $(document).ready(function () {
        $( '#mybundle_evenement_debut' ).datetimepicker({
            startDate: new Date(),
            format: 'd/m/y H:i',
            autoclose: true,

        });
    });
</script>

How would you fix this?