public static function dateFormat($model, $attribute, $options = [], $pickerOptions = [])
    {
        $pickerOptions = array_merge([
            'language' => Yii::$app->language == 'en' ? 'en-US' : Yii::$app->language,
            'model' => $model,
            'attribute' => $attribute,
            'options' => ['class' => 'form-control'],
        ], $pickerOptions);
        return array_merge([
            'attribute' => $attribute,
            'format' => 'date',
            'filter' => DatePicker::widget($pickerOptions)
        ], $options);
    }