Symfony 3.x form types demo from DevmachineFormBundle. You can access Symfony 2.x demo here.

->add('date', DateType::class, [
    'config' => [
        'clearBtn'       => true,
        'orientation'    => 'top',
        'todayHighlight' => true,
    ],
    'format' => 'dd/MM/y',
])
->add('date', DateType::class, [
    'input_addon' => true,
    'locale'      => 'ru',
])
->add('date', DateType::class, [
    'inline' => true,
])