diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 03009b3..49f0a31 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2195,15 +2195,15 @@ function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
  */
 function drupal_get_user_timezone() {
   global $user;
-  $config = config('system.date');
+  $config = config('system.timezone');
 
-  if ($config->get('timezone.user.configurable') && $user->uid && $user->timezone) {
+  if ($config->get('user.configurable') && $user->uid && $user->timezone) {
     return $user->timezone;
   }
   else {
     // Ignore PHP strict notice if time zone has not yet been set in the php.ini
     // configuration.
-    $config_data_default_timezone = $config->get('timezone.default');
+    $config_data_default_timezone = $config->get('default');
     return !empty($config_data_default_timezone) ? $config_data_default_timezone : @date_default_timezone_get();
   }
 }
diff --git a/core/includes/config.inc b/core/includes/config.inc
index 00c7fa6..31365e5 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -102,7 +102,7 @@ function config_get_storage_names_with_prefix($prefix = '') {
  *   A configuration object.
  */
 function config($name) {
-  return drupal_container()->get('config.factory')->get($name)->load();
+  return drupal_container()->get('config.factory')->get($name);
 }
 
 /**
@@ -141,11 +141,11 @@ function config_sync_get_changes(StorageInterface $source_storage, StorageInterf
     'delete' => array(),
   );
 
-  foreach (array_diff_assoc($target_config_data, $source_config_data) as $name => $value) {
+  foreach (array_diff_key($target_config_data, $source_config_data) as $name => $value) {
     $config_changes['delete'][] = $value['name'];
   }
 
-  foreach (array_diff_assoc($source_config_data, $target_config_data) as $name => $value) {
+  foreach (array_diff_key($source_config_data, $target_config_data) as $name => $value) {
     $config_changes['create'][] = $value['name'];
   }
 
@@ -190,6 +190,8 @@ function config_sync_changes(array $config_changes, StorageInterface $source_sto
       }
     }
   }
+  // Config might have changed, reset the stored config objects.
+  drupal_container()->get('config.factory')->resetConfigs();
 }
 
 /**
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 8e0e29c..ef50d04 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -2006,8 +2006,11 @@ function install_configure_form_submit($form, &$form_state) {
     ->set('mail', $form_state['values']['site_mail'])
     ->save();
 
+  config('system.timezone')
+    ->set('default', $form_state['values']['date_default_timezone'])
+    ->save();
+
   config('system.date')
-    ->set('timezone.default', $form_state['values']['date_default_timezone'])
     ->set('country.default', $form_state['values']['site_default_country'])
     ->save();
 
diff --git a/core/includes/module.inc b/core/includes/module.inc
index abe03dd..a924224 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -182,7 +182,7 @@ function system_list($type) {
       // Drupal installations, which might have modules installed in different
       // locations in the file system. The ordering here must also be
       // consistent with the one used in module_implements().
-      $enabled_modules = (array) config('system.module')->get('enabled');
+      $enabled_modules = (array) config('system.module')->init()->get('enabled');
       $module_files = state()->get('system.module.files');
       foreach ($enabled_modules as $name => $weight) {
         // Build a list of all enabled modules.
diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index 6fc2a87..c6a320e 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -65,6 +65,16 @@ class Config {
   protected $eventDispatcher;
 
   /**
+   * Whether the config object has already been loaded.
+   *
+   * Aside from TRUE or FALSE it can be NULL when inside load() to signal the
+   * "being loaded" phase.
+   *
+   * @var bool
+   */
+  protected $isLoaded = FALSE;
+
+  /**
    * Constructs a configuration object.
    *
    * @param string $name
@@ -88,6 +98,8 @@ public function __construct($name, StorageInterface $storage, EventDispatcher $e
    *   The configuration object.
    */
   public function init() {
+    $this->isLoaded = FALSE;
+    $this->overrides = array();
     $this->notify('init');
     return $this;
   }
@@ -120,6 +132,9 @@ public function setName($name) {
    *   TRUE if this config object does not exist in storage.
    */
   public function isNew() {
+    if (!$this->isLoaded) {
+      $this->load();
+    }
     return $this->isNew;
   }
 
@@ -151,6 +166,9 @@ public function isNew() {
    *   The data that was requested.
    */
   public function get($key = '') {
+    if (!$this->isLoaded) {
+      $this->load();
+    }
     if (!isset($this->overriddenData)) {
       $this->setOverriddenData();
     }
@@ -179,6 +197,11 @@ public function get($key = '') {
    *   The configuration object.
    */
   public function setData(array $data) {
+    // A load would destroy the data just set (for example on import). Do not
+    // set when inside load().
+    if (isset($this->isLoaded)) {
+      $this->isLoaded = TRUE;
+    }
     $this->data = $data;
     $this->resetOverriddenData();
     return $this;
@@ -243,6 +266,9 @@ protected function resetOverriddenData() {
    *   The configuration object.
    */
   public function set($key, $value) {
+    if (!$this->isLoaded) {
+      $this->load();
+    }
     // Type-cast value into a string.
     $value = $this->castValue($value);
 
@@ -309,6 +335,9 @@ public function castValue($value) {
    *   The configuration object.
    */
   public function clear($key) {
+    if (!$this->isLoaded) {
+      $this->load();
+    }
     $parts = explode('.', $key);
     if (count($parts) == 1) {
       unset($this->data[$key]);
@@ -327,6 +356,7 @@ public function clear($key) {
    *   The configuration object.
    */
   public function load() {
+    $this->isLoaded = NULL;
     $data = $this->storage->read($this->name);
     if ($data === FALSE) {
       $this->isNew = TRUE;
@@ -337,6 +367,7 @@ public function load() {
       $this->setData($data);
     }
     $this->notify('load');
+    $this->isLoaded = TRUE;
     return $this;
   }
 
@@ -347,6 +378,9 @@ public function load() {
    *   The configuration object.
    */
   public function save() {
+    if (!$this->isLoaded) {
+      $this->load();
+    }
     $this->storage->write($this->name, $this->data);
     $this->isNew = FALSE;
     $this->notify('save');
@@ -412,8 +446,12 @@ protected function notify($config_event_name) {
    *   The configuration object.
    */
   public function merge(array $data_to_merge) {
+    if (!$this->isLoaded) {
+      $this->load();
+    }
     // Preserve integer keys so that config keys are not changed.
     $this->data = NestedArray::mergeDeepArray(array($this->data, $data_to_merge), TRUE);
+    $this->resetOverriddenData();
     return $this;
   }
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index ca36ce7..826105a 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -38,6 +38,8 @@ class ConfigFactory {
    */
   protected $eventDispatcher;
 
+  protected $configs = array();
+
   /**
    * Constructs the Config factory.
    *
@@ -64,26 +66,15 @@ public function __construct(StorageInterface $storage, EventDispatcher $event_di
   public function get($name) {
     global $conf;
 
-    // @todo Caching the instantiated objects per name might cut off a fair
-    //   amount of CPU time and memory. Only the data within the configuration
-    //   object changes, so the additional cost of instantiating duplicate
-    //   objects could possibly be avoided. It is not uncommon for a
-    //   configuration object to be retrieved many times during a single
-    //   request; e.g., 'system.performance' alone is retrieved around 10-20
-    //   times within a single page request. Sub-requests via HttpKernel will
-    //   most likely only increase these counts.
-    // @todo Benchmarks were performed with a script that essentially retained
-    //   all instantiated configuration objects in memory until script execution
-    //   ended. A variant of that script called config() within a helper
-    //   function only, which inherently meant that PHP destroyed all
-    //   configuration objects after leaving the function. Consequently,
-    //   benchmark results looked entirely different. Profiling should probably
-    //   redone under more realistic conditions; e.g., actual HTTP requests.
-    // @todo The decrease of CPU time is interesting, since that means that
-    //   ContainerBuilder involves plenty of function calls (which are known to
-    //   be slow in PHP).
-    $config = new Config($name, $this->storage, $this->eventDispatcher);
-    return $config->init();
+    if (isset($this->configs[$name])) {
+      return $this->configs[$name];
+    }
+
+    $this->configs[$name] = new Config($name, $this->storage, $this->eventDispatcher);
+    return $this->configs[$name]->init();
   }
 
+  function resetConfigs() {
+    $this->configs = array();
+  }
 }
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
index 6d0a3f4..af37199 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
@@ -287,9 +287,10 @@ public function save(EntityInterface $entity) {
       $id = $entity->getOriginalID();
     }
     $config = config($prefix . $id);
+    $is_new = $config->isNew();
     $config->setName($prefix . $entity->id());
 
-    if (!$config->isNew() && !isset($entity->original)) {
+    if (!$is_new && !isset($entity->original)) {
       $this->resetCache(array($id));
       $result = $this->load(array($id));
       $entity->original = reset($result);
@@ -303,7 +304,7 @@ public function save(EntityInterface $entity) {
       $config->set($key, $value);
     }
 
-    if (!$config->isNew()) {
+    if (!$is_new) {
       $return = SAVED_UPDATED;
       $config->save();
       $this->postSave($entity, TRUE);
@@ -382,6 +383,11 @@ protected function postSave(EntityInterface $entity, $update) {
     if ($update && !empty($entity->original) && $entity->{$this->idKey} !== $entity->original->{$this->idKey}) {
       // @todo This should just delete the original config object without going
       //   through the API, no?
+      // @todo: We try to delete the original here, but because ConfigFactory
+      //   still things the new one that has been renamed is the original, we
+      //   end up deleting the new config file instead of the old one. Clearing
+      //   the cache fixes this, but isn't the correct approach.
+      drupal_container()->get('config.factory')->resetConfigs();
       $entity->original->delete();
     }
   }
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php
index 8e83a84..e2ddb59 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php
@@ -64,7 +64,7 @@ function testConfOverride() {
     $this->assertIdentical($config->get('404'), $expected_original_data['404']);
 
     // Reload the configuration object.
-    $config = config('config_test.system');
+    $config->init();
 
     // Verify that it contains the overridden data from $conf.
     $this->assertIdentical($config->get('foo'), $conf['config_test.system']['foo']);
@@ -97,7 +97,7 @@ function testConfOverride() {
     unset($conf['config_test.system']);
 
     // Reload it and verify that it still contains the original data.
-    $config = config('config_test.system');
+    $config->init();
     $this->assertIdentical($config->get('foo'), $expected_original_data['foo']);
     $this->assertIdentical($config->get('baz'), $expected_original_data['baz']);
     $this->assertIdentical($config->get('404'), $expected_original_data['404']);
diff --git a/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php b/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php
index adfe0b9..0ae38a3 100644
--- a/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php
+++ b/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php
@@ -37,7 +37,7 @@ function testLocaleConfigOverride() {
     // Spoof multilingual.
     $GLOBALS['conf']['language_count'] = 2;
     drupal_language_initialize();
-    $config = config($name);
+    $config->init();
     $this->assertIdentical($config->get('foo'), 'en bar');
   }
 }
diff --git a/core/modules/openid/lib/Drupal/openid/Tests/OpenIDRegistrationTest.php b/core/modules/openid/lib/Drupal/openid/Tests/OpenIDRegistrationTest.php
index d8847c1..99a1536 100644
--- a/core/modules/openid/lib/Drupal/openid/Tests/OpenIDRegistrationTest.php
+++ b/core/modules/openid/lib/Drupal/openid/Tests/OpenIDRegistrationTest.php
@@ -42,9 +42,9 @@ function setUp() {
   function testRegisterUserWithEmailVerification() {
     config('user.settings')->set('verify_mail', TRUE)->save();
 
-    config('system.date')
-      ->set('timezone.user.configurable', 1)
-      ->set('timezone.default', 'Europe/Brussels')
+    config('system.timezone')
+      ->set('user.configurable', 1)
+      ->set('default', 'Europe/Brussels')
       ->save();
 
     // Tell openid_test.module to respond with these SREG fields.
@@ -101,9 +101,9 @@ function testRegisterUserWithEmailVerification() {
   function testRegisterUserWithoutEmailVerification() {
     config('user.settings')->set('verify_mail', FALSE)->save();
 
-    config('system.date')
-      ->set('timezone.user.configurable', 1)
-      ->set('timezone.default', 'Europe/Brussels')
+    config('system.timezone')
+      ->set('user.configurable', 1)
+      ->set('default', 'Europe/Brussels')
       ->save();
 
     // Tell openid_test.module to respond with these SREG fields.
@@ -143,9 +143,9 @@ function testRegisterUserWithoutEmailVerification() {
    * information (a username that is already taken, and no e-mail address).
    */
   function testRegisterUserWithInvalidSreg() {
-    config('system.date')
-      ->set('timezone.user.configurable', 1)
-      ->set('timezone.default', 'Europe/Brussels')
+    config('system.timezone')
+      ->set('user.configurable', 1)
+      ->set('default', 'Europe/Brussels')
       ->save();
 
     // Tell openid_test.module to respond with these SREG fields.
@@ -233,8 +233,8 @@ function testRegisterUserWithoutSreg() {
    */
   function testRegisterUserWithAXButNoSREG() {
     config('user.settings')->set('verify_mail', FALSE)->save();
-    config('system.date')
-      ->set('timezone.default', 'Europe/Brussels')
+    config('system.timezone')
+      ->set('default', 'Europe/Brussels')
       ->save();
 
     // Tell openid_test.module to respond with these AX fields.
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 001e521..cb62f0c 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -1227,6 +1227,7 @@ protected function drupalPost($path, $edit, $submit, array $options = array(), a
           $out = $this->curlExec(array(CURLOPT_URL => $action, CURLOPT_POST => TRUE, CURLOPT_POSTFIELDS => $post, CURLOPT_HTTPHEADER => $headers));
           // Ensure that any changes to variables in the other thread are picked up.
           $this->refreshVariables();
+          drupal_container()->get('config.factory')->resetConfigs();
 
           // Replace original page output with new output from redirected page(s).
           if ($new = $this->checkForMetaRefresh()) {
diff --git a/core/modules/system/config/system.date.yml b/core/modules/system/config/system.date.yml
index ab21797..82a22bc 100644
--- a/core/modules/system/config/system.date.yml
+++ b/core/modules/system/config/system.date.yml
@@ -1,12 +1,6 @@
 first_day: '0'
 country:
   default: ''
-timezone:
-  default: ''
-  user:
-    configurable: '1'
-    default: '0'
-    warn: '0'
 formats:
   long:
     name: 'Default Long Date'
diff --git a/core/modules/system/config/system.timezone.yml b/core/modules/system/config/system.timezone.yml
new file mode 100644
index 0000000..b0d33a1
--- /dev/null
+++ b/core/modules/system/config/system.timezone.yml
@@ -0,0 +1,5 @@
+default: ''
+user:
+  configurable: '1'
+  default: '0'
+  warn: '0'
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
index e89a302..1edc236 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
@@ -36,8 +36,10 @@ public static function getInfo() {
 
   function setUp() {
     parent::setUp('language');
+    config('system.timezone')
+      ->set('user.configurable', 1)
+      ->save();
     config('system.date')
-      ->set('timezone.user.configurable', 1)
       ->set('formats.long.pattern.php', 'l, j. F Y - G:i')
       ->set('formats.medium.pattern.php', 'j. F Y - G:i')
       ->set('formats.short.pattern.php', 'Y M j - g:ia')
diff --git a/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php b/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php
index 5539a61..698ea1a 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php
@@ -48,8 +48,10 @@ public function testDateTimezone() {
     $date_string = '2007-01-31 21:00:00';
 
     // Make sure no site timezone has been set.
-    config('system.date')->set('timezone.default', NULL)->save();
-    config('system.date')->set('timezone.user.configurable', 0)->save();
+    config('system.timezone')
+      ->set('user.configurable', 0)
+      ->set('default', NULL)
+      ->save();
 
     // Detect the system timezone.
     $system_timezone = date_default_timezone_get();
@@ -66,7 +68,7 @@ public function testDateTimezone() {
     $this->assertTrue($timezone == 'America/Yellowknife', 'DrupalDateTime uses the specified timezone if provided.');
 
     // Set a site timezone.
-    config('system.date')->set('timezone.default', 'Europe/Warsaw')->save();
+    config('system.timezone')->set('default', 'Europe/Warsaw')->save();
 
     // Create a date object with an unspecified timezone, which should
     // end up using the site timezone.
@@ -75,7 +77,7 @@ public function testDateTimezone() {
     $this->assertTrue($timezone == 'Europe/Warsaw', 'DrupalDateTime uses the site timezone if provided.');
 
     // Create user.
-    config('system.date')->set('timezone.user.configurable', 1)->save();
+    config('system.timezone')->set('user.configurable', 1)->save();
     $test_user = $this->drupalCreateUser(array());
     $this->drupalLogin($test_user);
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsLanguageTest.php b/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsLanguageTest.php
index ff16e61..459b498 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsLanguageTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsLanguageTest.php
@@ -100,6 +100,7 @@ function testLocalizeDateFormats() {
     // Configure format for the node posted date changes with the language.
     $this->drupalGet('node/' . $node->nid);
     $english_date = format_date($node->created, 'custom', 'j M Y');
+    debug($english_date);
     $this->assertText($english_date, 'English date format appears');
     $this->drupalGet('fr/node/' . $node->nid);
     $french_date = format_date($node->created, 'custom', 'd.m.Y');
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/DateTimeTest.php b/core/modules/system/lib/Drupal/system/Tests/System/DateTimeTest.php
index 2c6571a..7a0f5c0 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/DateTimeTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/DateTimeTest.php
@@ -43,9 +43,11 @@ function setUp() {
    */
   function testTimeZoneHandling() {
     // Setup date/time settings for Honolulu time.
-    $config = config('system.date')
-      ->set('timezone.default', 'Pacific/Honolulu')
-      ->set('timezone.user.configurable', 0)
+    $config = config('system.timezone')
+      ->set('default', 'Pacific/Honolulu')
+      ->set('user.configurable', 0)
+      ->save();
+    config('system.date')
       ->set('formats.medium.pattern.php', 'Y-m-d H:i:s O')
       ->save();
 
@@ -62,7 +64,7 @@ function testTimeZoneHandling() {
     $this->assertText('2007-07-31 21:00:00 -1000', 'Date should be identical, with GMT offset of -10 hours.');
 
     // Set time zone to Los Angeles time.
-    $config->set('timezone.default', 'America/Los_Angeles')->save();
+    $config->set('default', 'America/Los_Angeles')->save();
 
     // Confirm date format and time zone.
     $this->drupalGet("node/$node1->nid");
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index b8cae7a..826a2f1 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -1866,7 +1866,7 @@ function system_rss_feeds_settings_submit($form, &$form_state) {
  */
 function system_regional_settings($form, &$form_state) {
   $countries = country_get_list();
-  $system_date = config('system.date');
+  $system_timezone = config('system.timezone');
   $system_date = config('system.date');
 
   // Date settings:
@@ -1898,16 +1898,14 @@ function system_regional_settings($form, &$form_state) {
     '#title' => t('Time zones'),
   );
 
-  $date_default_timezone = $system_date->get('timezone.default');
-  $date_default_timezone = $system_date->get('timezone.default');
   $form['timezone']['date_default_timezone'] = array(
     '#type' => 'select',
     '#title' => t('Default time zone'),
-    '#default_value' => isset($date_default_timezone) ? $date_default_timezone : date_default_timezone_get(),
+    '#default_value' => $system_timezone->get('default') ?: date_default_timezone_get(),
     '#options' => $zones,
   );
 
-  $configurable_timezones = $system_date->get('timezone.user.configurable');
+  $configurable_timezones = $system_timezone->get('user.configurable');
   $form['timezone']['configurable_timezones'] = array(
     '#type' => 'checkbox',
     '#title' => t('Users may set their own time zone.'),
@@ -1927,14 +1925,14 @@ function system_regional_settings($form, &$form_state) {
   $form['timezone']['configurable_timezones_wrapper']['empty_timezone_message'] = array(
     '#type' => 'checkbox',
     '#title' => t('Remind users at login if their time zone is not set.'),
-    '#default_value' => $system_date->get('timezone.user.warn'),
+    '#default_value' => $system_timezone->get('user.warn'),
     '#description' => t('Only applied if users may set their own time zone.')
   );
 
   $form['timezone']['configurable_timezones_wrapper']['user_default_timezone'] = array(
     '#type' => 'radios',
     '#title' => t('Time zone for new users'),
-    '#default_value' => $system_date->get('timezone.user.default'),
+    '#default_value' => $system_timezone->get('user.default'),
     '#options' => array(
       DRUPAL_USER_TIMEZONE_DEFAULT => t('Default time zone.'),
       DRUPAL_USER_TIMEZONE_EMPTY   => t('Empty time zone.'),
@@ -1956,10 +1954,12 @@ function system_regional_settings_submit($form, &$form_state) {
   config('system.date')
     ->set('country.default', $form_state['values']['site_default_country'])
     ->set('first_day', $form_state['values']['date_first_day'])
-    ->set('timezone.default', $form_state['values']['date_default_timezone'])
-    ->set('timezone.user.configurable', $form_state['values']['configurable_timezones'])
-    ->set('timezone.user.warn', $form_state['values']['empty_timezone_message'])
-    ->set('timezone.user.default', $form_state['values']['user_default_timezone'])
+    ->save();
+  config('system.timezone')
+    ->set('default', $form_state['values']['date_default_timezone'])
+    ->set('user.configurable', $form_state['values']['configurable_timezones'])
+    ->set('user.warn', $form_state['values']['empty_timezone_message'])
+    ->set('user.default', $form_state['values']['user_default_timezone'])
     ->save();
 }
 
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index be3a6d8..59d9508 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -2286,9 +2286,12 @@ function system_update_8038() {
     'site_default_country' => 'country.default',
     'date_first_day' => 'first_day',
     'date_default_timezone' => 'timezone.default',
-    'configurable_timezones' => 'timezone.user.configurable',
-    'empty_timezone_message' => 'timezone.user.warn',
-    'user_default_timezone' => 'timezone.user.default',
+  ));
+  update_variables_to_config('system.timezone', array(
+    'date_default_timezone' => 'default',
+    'configurable_timezones' => 'user.configurable',
+    'empty_timezone_message' => 'user.warn',
+    'user_default_timezone' => 'user.default',
   ));
 }
 
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 26fee90..a1d919a 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -2403,7 +2403,7 @@ function system_custom_theme() {
  * Implements hook_form_FORM_ID_alter().
  */
 function system_form_user_profile_form_alter(&$form, &$form_state) {
-  if (config('system.date')->get('timezone.user.configurable')) {
+  if (config('system.timezone')->get('user.configurable')) {
     system_user_timezone($form, $form_state);
   }
   return $form;
@@ -2413,8 +2413,8 @@ function system_form_user_profile_form_alter(&$form, &$form_state) {
  * Implements hook_form_FORM_ID_alter().
  */
 function system_form_user_register_form_alter(&$form, &$form_state) {
-  $config = config('system.date');
-  if ($config->get('timezone.user.configurable') && $config->get('timezone.user.default') == DRUPAL_USER_TIMEZONE_SELECT) {
+  $config = config('system.timezone');
+  if ($config->get('user.configurable') && $config->get('user.default') == DRUPAL_USER_TIMEZONE_SELECT) {
     system_user_timezone($form, $form_state);
     return $form;
   }
@@ -2424,9 +2424,9 @@ function system_form_user_register_form_alter(&$form, &$form_state) {
  * Implements hook_user_presave().
  */
 function system_user_presave($account) {
-  $config = config('system.date');
-  if ($config->get('timezone.user.configurable') && empty($account->timezone) && !$config->get('timezone.user.default')) {
-    $account->timezone = $config->get('timezone.default');
+  $config = config('system.timezone');
+  if ($config->get('user.configurable') && empty($account->timezone) && !$config->get('user.default')) {
+    $account->timezone = $config->get('default');
   }
 }
 
@@ -2434,9 +2434,9 @@ function system_user_presave($account) {
  * Implements hook_user_login().
  */
 function system_user_login($edit, $account) {
-  $config = config('system.date');
+  $config = config('system.timezone');
   // If the user has a NULL time zone, notify them to set a time zone.
-  if (!$account->timezone && $config->get('timezone.user.configurable') && $config->get('timezone.user.warn')) {
+  if (!$account->timezone && $config->get('user.configurable') && $config->get('user.warn')) {
     drupal_set_message(t('Configure your <a href="@user-edit">account time zone setting</a>.', array('@user-edit' => url("user/$account->uid/edit", array('query' => drupal_get_destination(), 'fragment' => 'edit-timezone')))));
   }
 }
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
index 0b96373..30164f0 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
@@ -157,9 +157,9 @@ function testRegistrationDefaultValues() {
       ->save();
 
     // Set the default timezone to Brussels.
-    $config_system_date = config('system.date')
-      ->set('timezone.user.configurable', 1)
-      ->set('timezone.default', 'Europe/Brussels')
+    $config_system_timezone = config('system.timezone')
+      ->set('user.configurable', 1)
+      ->set('default', 'Europe/Brussels')
       ->save();
 
     // Check that the account information options are not displayed
@@ -183,7 +183,7 @@ function testRegistrationDefaultValues() {
     $this->assertEqual($new_user->signature, '', 'Correct signature field.');
     $this->assertTrue(($new_user->created > REQUEST_TIME - 20 ), 'Correct creation time.');
     $this->assertEqual($new_user->status, $config_user_settings->get('register') == USER_REGISTER_VISITORS ? 1 : 0, 'Correct status field.');
-    $this->assertEqual($new_user->timezone, $config_system_date->get('timezone.default'), 'Correct time zone field.');
+    $this->assertEqual($new_user->timezone, $config_system_timezone->get('default'), 'Correct time zone field.');
     $this->assertEqual($new_user->langcode, language_default()->langcode, 'Correct language field.');
     $this->assertEqual($new_user->preferred_langcode, language_default()->langcode, 'Correct preferred language field.');
     $this->assertEqual($new_user->init, $mail, 'Correct init field.');
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php b/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php
index 575bfc1..8b77915 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php
@@ -26,9 +26,11 @@ public static function getInfo() {
    */
   function testUserTimeZone() {
     // Setup date/time settings for Los Angeles time.
-    $config = config('system.date')
-      ->set('timezone.user.configurable', 1)
-      ->set('timezone.default', 'America/Los_Angeles')
+    config('system.timezone')
+      ->set('user.configurable', 1)
+      ->set('default', 'America/Los_Angeles')
+      ->save();
+    config('system.date')
       ->set('formats.medium.pattern.php', 'Y-m-d H:i T')
       ->save();
 
diff --git a/core/modules/user/user.api.php b/core/modules/user/user.api.php
index 1c68427..88d23a9 100644
--- a/core/modules/user/user.api.php
+++ b/core/modules/user/user.api.php
@@ -305,9 +305,9 @@ function hook_user_update($account) {
  *   The user object on which the operation was just performed.
  */
 function hook_user_login(&$edit, $account) {
-  $config = config('system.date');
+  $config = config('system.timezone');
   // If the user has a NULL time zone, notify them to set a time zone.
-  if (!$account->timezone && $config->get('timezone.user.configurable') && $config->get('timezone.user.warn')) {
+  if (!$account->timezone && $config->get('user.configurable') && $config->get('user.warn')) {
     drupal_set_message(t('Configure your <a href="@user-edit">account time zone setting</a>.', array('@user-edit' => url("user/$account->uid/edit", array('query' => drupal_get_destination(), 'fragment' => 'edit-timezone')))));
   }
 }