Adding readOnly to Date or Datetime fields brook the date configured format #258

Hi,
When I set a datetime or date field as Readonly it don't take the format :

in the show method of my Crud config file I have multiple dates

 $form->dt('created_at', 'd/m/Y H:i')
                ->title('Created At')
                ->readonly()
            ;

            $form->date('updated_at', 'd/m/Y H:i')
                ->title('Updated At')
                ->readOnly();

it render the form like this :

when I remove the readOnly , it shows :

it seems that the readOnly brook the formatting params for date and datetime !!

Thanks.