Now Symfony DateType has 3 widget types: `choice`, `text`, `single_text`. When using widget type `choice` the format is `y-M-d` and can't be changed, see: https://github.com/symfony/symfony/blob/v3.3.0/src/Symfony/Component/Form/Extension/Core/Type/DateType.php#L73 We have business requirement, that months always must be rendered as numbers (from 01 to 12). What is the best way to achieve this?