I\'m Using Kartik DateTimePicker Extension
= $form->field($model, \'Created\')->widget(DateTimePicker::classname(),[
\'model\' => $model,
Need to just add this code before save/update model in controller.
like,
// ICU format
$model->Created = Yii::$app->formatter->asDate($_POST['modelName']['Created'], 'yyyy-MM-dd HH:mm:ss'); // 2014-10-06 15:22:34
OR
// PHP date()-format
$model->Created = Yii::$app->formatter->asDate($_POST['modelName']['Created'], 'php:Y-m-d H:i:s'); // 2014-10-06 15:22:34
For more information refer this link