diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 8651134..534a597 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -537,4 +537,12 @@ protected function getModuleNamespaces($moduleFileNames) {
   protected function registerNamespaces(array $namespaces = array()) {
     $this->classLoader->addPrefixes($namespaces);
   }
+
+  public function serialize() {
+    return serialize(array($this->environment, $this->debug, $this->classLoader, $this->allowDumping));
+  }
+  public function unserialize($data) {
+    list($environment, $debug, $class_loader, $allow_dumping) = unserialize($data);
+    $this->__construct($environment, $debug, $class_loader, $allow_dumping);
+  }
 }
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php b/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php
index 1201e6d..6dec855 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Datetime\DrupalDateTime;
-
 /**
  * Provides an add form for date formats.
  */
@@ -34,8 +32,6 @@ public function buildForm(array $form, array &$form_state) {
       '#default_value' => '',
     );
 
-    $now = '';
-
     $form['date_format_id'] = array(
       '#type' => 'machine_name',
       '#title' => t('Machine-readable name'),
@@ -58,8 +54,8 @@ public function buildForm(array $form, array &$form_state) {
       '#title' => t('Format string'),
       '#maxlength' => 100,
       '#description' => $description,
-      '#default_value' => empty($pattern) ? '' : $pattern,
-      '#field_suffix' => ' <small id="edit-date-format-suffix">' . $now . '</small>',
+      '#default_value' => '',
+      '#field_suffix' => ' <small id="edit-date-format-suffix"></small>',
       '#ajax' => array(
         'callback' => 'system_date_time_lookup',
         'event' => 'keyup',
@@ -95,4 +91,3 @@ public function buildForm(array $form, array &$form_state) {
   }
 
 }
-
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php b/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php
index 62c7495..56afe28 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php
@@ -7,12 +7,42 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Datetime\DrupalDateTime;
+use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\ControllerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Provides an edit form for date formats.
  */
-class DateFormatEditForm extends DateFormatFormBase {
+class DateFormatEditForm extends DateFormatFormBase implements ControllerInterface {
+
+  /**
+   * The config object.
+   *
+   * @var \Drupal\Core\Config\Config
+   */
+  protected $config;
+
+  /**
+   * Constructs a new date format form.
+   *
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The config factory object.
+   */
+  public function __construct(ConfigFactory $config_factory) {
+    parent::__construct();
+
+    $this->config = $config_factory->get('system.date');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('config.factory')
+    );
+  }
 
   /**
    * {@inheritdoc}
@@ -26,10 +56,8 @@ public function getFormID() {
    */
   public function buildForm(array $form, array &$form_state, $date_format_id = NULL) {
     form_load_include($form_state, 'admin.inc', 'system');
-    $format_info = config('system.date')->get('formats.' . $date_format_id);
-    $patterns = $format_info['pattern'];
-    $date = new DrupalDateTime();
-    $pattern = $date->canUseIntl() ? $patterns[DrupalDateTime::INTL] : $patterns[DrupalDateTime::PHP];
+    $format_info = $this->config->get('formats.' . $date_format_id);
+    $pattern = $this->patternType ? $format_info['pattern'][$this->patternType] : '';
 
     $form['date_format_name'] = array(
       '#type' => 'textfield',
@@ -64,7 +92,7 @@ public function buildForm(array $form, array &$form_state, $date_format_id = NUL
       '#title' => t('Format string'),
       '#maxlength' => 100,
       '#description' => $description,
-      '#default_value' => empty($pattern) ? '' : $pattern,
+      '#default_value' => $pattern,
       '#field_suffix' => ' <small id="edit-date-format-suffix">' . $now . '</small>',
       '#ajax' => array(
         'callback' => 'system_date_time_lookup',
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php b/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php
index 536e03f..eef17d8 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Datetime\DrupalDateTime;
 use Drupal\Core\Form\FormInterface;
+use Drupal\Component\Utility\String;
 
 /**
  * Provides a base form for date formats.
@@ -16,6 +17,21 @@
 abstract class DateFormatFormBase implements FormInterface {
 
   /**
+   * The date pattern type.
+   *
+   * @var string
+   */
+  protected $patternType;
+
+  /**
+   * Constructs a new date format form.
+   */
+  public function __construct() {
+    $date = new DrupalDateTime();
+    $this->patternType = $date->canUseIntl() ? DrupalDateTime::INTL : DrupalDateTime::PHP;
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function validateForm(array &$form, array &$form_state) {
@@ -34,11 +50,9 @@ public function validateForm(array &$form, array &$form_state) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, array &$form_state) {
-    $date = new DrupalDateTime();
-    $pattern_type = $date->canUseIntl() ? DrupalDateTime::INTL : DrupalDateTime::PHP;
     $format = array();
-    $format['name'] = check_plain($form_state['values']['date_format_name']);
-    $format['pattern'][$pattern_type] = trim($form_state['values']['date_format_pattern']);
+    $format['name'] = String::checkPlain($form_state['values']['date_format_name']);
+    $format['pattern'][$this->patternType] = trim($form_state['values']['date_format_pattern']);
     $format['locales'] = !empty($form_state['values']['date_langcode']) ? $form_state['values']['date_langcode'] : array();
     // Formats created in the UI are not locked.
     $format['locked'] = 0;