kartik date picker code example
Example: kartik datepicker
$form->field($model, 'attribute')->widget(DatePicker::classname(), [
'options' => ['placeholder' => 'Enter birth date ...'],
'pluginOptions' => [
'autoclose'=>true,
'todayHighlight' => true,
'format' => 'yyyy/mm/dd',?,'yyyy-mm-dd',
]
]);