diff --git a/core/includes/common.inc b/core/includes/common.inc
index 44fa367..d7c73f4 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1911,58 +1911,15 @@ function format_date($timestamp, $type = 'medium', $format = '', $timezone = NUL
     $langcode = language(LANGUAGE_TYPE_INTERFACE)->langcode;
   }
 
-  switch ($type) {
-    case 'short':
-      $format = variable_get('date_format_short', 'm/d/Y - H:i');
-      break;
-
-    case 'long':
-      $format = variable_get('date_format_long', 'l, F j, Y - H:i');
-      break;
-
-    case 'html_datetime':
-      $format = variable_get('date_format_html_datetime', 'Y-m-d\TH:i:sO');
-      break;
-
-    case 'html_date':
-      $format = variable_get('date_format_html_date', 'Y-m-d');
-      break;
-
-    case 'html_time':
-      $format = variable_get('date_format_html_time', 'H:i:s');
-      break;
-
-    case 'html_yearless_date':
-      $format = variable_get('date_format_html_yearless_date', 'm-d');
-      break;
-
-    case 'html_week':
-      $format = variable_get('date_format_html_week', 'Y-\WW');
-      break;
-
-    case 'html_month':
-      $format = variable_get('date_format_html_month', 'Y-m');
-      break;
-
-    case 'html_year':
-      $format = variable_get('date_format_html_year', 'Y');
-      break;
-
-    case 'custom':
-      // No change to format.
-      break;
-
-    case 'medium':
-    default:
-      // Retrieve the format of the custom $type passed.
-      if ($type != 'medium') {
-        $format = variable_get('date_format_' . $type, '');
-      }
-      // Fall back to 'medium'.
-      if ($format === '') {
-        $format = variable_get('date_format_medium', 'D, m/d/Y - H:i');
-      }
-      break;
+  if ($type != 'custom') {
+    // Retrieve the format of the custom $type passed.
+    $config = config('system.date_format_type');
+    $format = $config->get($type);
+
+    // Fall back to 'medium'.
+    if (empty($format)) {
+      $format = $config->get('medium');
+    }
   }
 
   // Create a DateTime object from the timestamp.
diff --git a/core/includes/form.inc b/core/includes/form.inc
index a142e69..b8964fc 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -2951,7 +2951,7 @@ function form_process_date($element) {
   $element['#tree'] = TRUE;
 
   // Determine the order of day, month, year in the site's chosen date format.
-  $format = variable_get('date_format_short', 'm/d/Y - H:i');
+  $format = config('system.date_format_type')->get('short');
   $sort = array();
   $sort['day'] = max(strpos($format, 'd'), strpos($format, 'j'));
   $sort['month'] = max(strpos($format, 'm'), strpos($format, 'M'));
diff --git a/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
index 78ca5bc..0c04c7d 100644
--- a/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -335,7 +335,7 @@ function template_preprocess_aggregator_item(&$variables) {
     $variables['source_date'] = t('%ago ago', array('%ago' => format_interval(REQUEST_TIME - $item->timestamp)));
   }
   else {
-    $variables['source_date'] = format_date($item->timestamp, 'custom', variable_get('date_format_medium', 'D, m/d/Y - H:i'));
+    $variables['source_date'] = format_date($item->timestamp, 'medium');
   }
 
   $variables['categories'] = array();
diff --git a/core/modules/system/config/system.date_format_type.yml b/core/modules/system/config/system.date_format_type.yml
new file mode 100644
index 0000000..60bffb2
--- /dev/null
+++ b/core/modules/system/config/system.date_format_type.yml
@@ -0,0 +1,10 @@
+long: 'l, F j, Y - H:i'
+medium: 'D, m/d/Y - H:i'
+short: 'm/d/Y - H:i'
+html_datetime: 'Y-m-d\TH:i:sO'
+html_date: 'Y-m-d'
+html_time: 'H:i:s'
+html_yearless_date: 'm-d'
+html_week: 'Y-\WW'
+html_month: 'Y-m'
+html_year: 'Y'
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 9639758..2f1a083 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
@@ -19,7 +19,7 @@ class FormatDateTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = array('language');
+  public static $modules = array('language', 'locale');
 
   /**
    * Arbitrary langcode for a custom language.
@@ -37,9 +37,11 @@ class FormatDateTest extends WebTestBase {
   function setUp() {
     parent::setUp();
     variable_set('configurable_timezones', 1);
-    variable_set('date_format_long', 'l, j. F Y - G:i');
-    variable_set('date_format_medium', 'j. F Y - G:i');
-    variable_set('date_format_short', 'Y M j - g:ia');
+    $config = config('system.date_format_type')
+      ->set('long', 'l, j. F Y - G:i')
+      ->set('medium', 'j. F Y - G:i')
+      ->set('short', 'Y M j - g:ia')
+      ->save();
     variable_set('locale_custom_strings_' . self::LANGCODE, array(
       '' => array('Sunday' => 'domingo'),
       'Long month name' => array('March' => 'marzo'),
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 2054180..2384f7d 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsLanguageTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsLanguageTest.php
@@ -61,16 +61,16 @@ class DateFormatsLanguageTest extends WebTestBase {
     $this->drupalGet('admin/config/regional/date-time/locale');
     $this->assertText('French', 'Configured languages appear.');
     $edit = array(
-      'date_format_long' => 'd.m.Y - H:i',
-      'date_format_medium' => 'd.m.Y - H:i',
-      'date_format_short' => 'd.m.Y - H:i',
+      'date_formats[long]' => 'd.m.Y - H:i',
+      'date_formats[medium]' => 'd.m.Y - H:i',
+      'date_formats[short]' => 'd.m.Y - H:i',
     );
     $this->drupalPost('admin/config/regional/date-time/locale/fr/edit', $edit, t('Save configuration'));
     $this->assertText(t('Configuration saved.'), 'French date formats updated.');
     $edit = array(
-      'date_format_long' => 'j M Y - g:ia',
-      'date_format_medium' => 'j M Y - g:ia',
-      'date_format_short' => 'j M Y - g:ia',
+      'date_formats[long]' => 'j M Y - g:ia',
+      'date_formats[medium]' => 'j M Y - g:ia',
+      'date_formats[short]' => 'j M Y - g:ia',
     );
     $this->drupalPost('admin/config/regional/date-time/locale/en/edit', $edit, t('Save configuration'));
     $this->assertText(t('Configuration saved.'), 'English date formats updated.');
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 6494a4a..af1ab88 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/DateTimeTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/DateTimeTest.php
@@ -46,7 +46,9 @@ class DateTimeTest extends WebTestBase {
     // Setup date/time settings for Honolulu time.
     variable_set('date_default_timezone', 'Pacific/Honolulu');
     variable_set('configurable_timezones', 0);
-    variable_set('date_format_medium', 'Y-m-d H:i:s O');
+    config('system.date_format_type')
+      ->set('medium', 'Y-m-d H:i:s O')
+      ->save();
 
     // Create some nodes with different authored-on dates.
     $date1 = '2007-01-31 21:00:00 -1000';
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index 72c50d4..90b23bc 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -2039,12 +2039,13 @@ function system_regional_settings() {
  * Form builder; Configure the site date and time settings.
  *
  * @ingroup forms
- * @see system_settings_form()
+ * @see system_date_time_settings_submit()
  */
-function system_date_time_settings() {
+function system_date_time_settings($form, &$form_state) {
   // Get list of all available date types.
   drupal_static_reset('system_get_date_types');
   $format_types = system_get_date_types();
+  $config = config('system.date_format_type');
 
   // Get list of all available date formats.
   $all_formats = array();
@@ -2077,14 +2078,15 @@ function system_date_time_settings() {
         $choices[$f] = format_date(REQUEST_TIME, 'custom', $f);
       }
       reset($formats);
-      $default = variable_get('date_format_' . $type, key($formats));
+      $default = $config->get($type);
 
       // Get date type info for this date type.
       $type_info = system_get_date_types($type);
       $form['formats']['#theme'] = 'system_date_time_settings';
 
       // Show date format select list.
-      $form['formats']['format']['date_format_' . $type] = array(
+      $form['formats']['format']['#tree'] = TRUE;
+      $form['formats']['format'][$type] = array(
         '#type' => 'select',
         '#title' => check_plain($type_info['title']),
         '#attributes' => array('class' => array('date-format')),
@@ -2095,7 +2097,8 @@ function system_date_time_settings() {
       // If this isn't a system provided type, allow the user to remove it from
       // the system.
       if ($type_info['locked'] == 0) {
-        $form['formats']['delete']['date_format_' . $type . '_delete'] = array(
+        $form['formats']['delete']['#tree'] = TRUE;
+        $form['formats']['delete'][$type] = array(
           '#type' => 'link',
           '#title' => t('delete'),
           '#href' => 'admin/config/regional/date-time/types/' . $type . '/delete',
@@ -2107,7 +2110,18 @@ function system_date_time_settings() {
   // Display a message if no date types configured.
   $form['#empty_text'] = t('No date types available. <a href="@link">Add date type</a>.', array('@link' => url('admin/config/regional/date-time/types/add')));
 
-  return system_settings_form($form);
+  return system_config_form($form, $form_state);
+}
+
+/**
+ * Form submission handler for system_date_time_settings().
+ */
+function system_date_time_settings_submit($form, &$form_state) {
+  $config = config('system.date_format_type');
+  foreach ($form_state['values']['format'] as $format_type => $value) {
+    $config->set($format_type, $value);
+  }
+  $config->save();
 }
 
 /**
@@ -2228,8 +2242,9 @@ function system_add_date_format_type_form_submit($form, &$form_state) {
   $format_type['locked'] = 0;
   $format_type['is_new'] = 1;
   system_date_format_type_save($format_type);
-  variable_set('date_format_' . $machine_name, $form_state['values']['date_format']);
-
+  config('system.date_format_type')
+    ->set($machine_name, $form_state['values']['date_format'])
+    ->save();
   drupal_set_message(t('New date type added successfully.'));
   $form_state['redirect'] = 'admin/config/regional/date-time';
 }
@@ -3263,16 +3278,17 @@ function system_date_format_localize_form($form, &$form_state, $langcode) {
   // Get configured formats for each language.
   $locale_formats = system_date_format_locale($langcode);
   // Display a form field for each format type.
+  $form['date_formats']['#tree'] = TRUE;
   foreach ($types as $type => $type_info) {
     if (!empty($locale_formats) && in_array($type, array_keys($locale_formats))) {
       $default = $locale_formats[$type];
     }
     else {
-      $default = variable_get('date_format_' . $type, key($formats));
+      $default = config('system.date_format_type')->get($type);
     }
 
     // Show date format select list.
-    $form['date_formats']['date_format_' . $type] = array(
+    $form['date_formats'][$type] = array(
       '#type' => 'select',
       '#title' => check_plain($type_info['title']),
       '#attributes' => array('class' => array('date-format')),
@@ -3299,10 +3315,7 @@ function system_date_format_localize_form_submit($form, &$form_state) {
   // Get list of date format types.
   $types = system_get_date_types();
   foreach ($types as $type => $type_info) {
-    $format = $form_state['values']['date_format_' . $type];
-    if ($format == 'custom') {
-      $format = $form_state['values']['date_format_' . $type . '_custom'];
-    }
+    $format = $form_state['values']['date_formats'][$type];
     system_date_format_localize_form_save($langcode, $type, $format);
   }
   drupal_set_message(t('Configuration saved.'));
diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index de8a2ae..c058f73 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -3520,7 +3520,7 @@ function hook_archiver_info_alter(&$info) {
  *
  * To define a date type in a module and make sure a format has been assigned to
  * it, without requiring a user to visit the administrative interface, use
- * @code variable_set('date_format_' . $type, $format); @endcode
+ * @code config('system.date_format_type')->set($type, $format); @endcode
  * where $type is the machine-readable name defined here, and $format is a PHP
  * date format string.
  *
@@ -3590,7 +3590,7 @@ function hook_date_format_types_alter(&$types) {
  * initialization chooses a locale-specific format for the three core-provided
  * types (see system_get_localized_date_format() for details). If your module
  * needs to ensure that a date type it defines has a format associated with it,
- * call @code variable_set('date_format_' . $type, $format); @endcode
+ * call @code config('system.date_format_type')->set($type, $format); @endcode
  * where $type is the machine-readable name defined in hook_date_format_types(),
  * and $format is a PHP date format string.
  *
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index b8d402c..f44d2a6 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -2062,6 +2062,22 @@ function system_update_8017() {
 }
 
 /**
+  * Moves systems date format settings from variables to config.
+  * Find all the variables that match the 'date_format_TYPE' pattern
+  * for conversion to config.
+  *
+  * @ingroup config_upgrade
+  */
+function system_update_8018() {
+  $variables = array();
+  $format_types = db_query("SELECT name, value FROM {variable} WHERE name LIKE 'date_format_%'")->fetchAll();
+  foreach ($format_types as $type) {
+    $variables[$type->name] = trim(str_replace('date_format_', '', $type->name));
+  }
+  update_variables_to_config('system.date_format_type', $variables);
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x".
  * The next series of updates should start at 9000.
  */
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 69a1f62..259b08c 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -2086,7 +2086,7 @@ function system_init() {
     // Setup appropriate date formats for this locale.
     $formats = system_get_localized_date_format($languages);
     foreach ($formats as $format_type => $format) {
-      $conf[$format_type] = $format;
+      $conf['system.date_format_type'][$format_type] = $format;
     }
   }
 
@@ -2136,10 +2136,11 @@ function system_init() {
  */
 function system_get_localized_date_format($languages) {
   $formats = array();
+  $config = config('system.date_format_type');
 
   // Get list of different format types.
   $format_types = system_get_date_types();
-  $short_default = variable_get('date_format_short', 'm/d/Y - H:i');
+  $short_default = $config->get('short');
 
   // Loop through each language until we find one with some date formats
   // configured.
@@ -2151,12 +2152,13 @@ function system_get_localized_date_format($languages) {
       foreach ($format_types as $type => $type_info) {
         // If format exists for this language, use it.
         if (!empty($date_formats[$type])) {
-          $formats['date_format_' . $type] = $date_formats[$type];
+          $formats[$type] = $date_formats[$type];
         }
         // Otherwise get default variable setting. If this is not set, default
         // to the short format.
         else {
-          $formats['date_format_' . $type] = variable_get('date_format_' . $type, $short_default);
+          $default = $config->get( $type);
+          $formats[$type] = !empty($default) ? $default : $short_default;
         }
       }
 
@@ -2168,15 +2170,16 @@ function system_get_localized_date_format($languages) {
   // No locale specific formats found, so use defaults.
   $system_types = array('short', 'medium', 'long');
   // Handle system types separately as they have defaults if no variable exists.
-  $formats['date_format_short'] = $short_default;
-  $formats['date_format_medium'] = variable_get('date_format_medium', 'D, m/d/Y - H:i');
-  $formats['date_format_long'] = variable_get('date_format_long', 'l, F j, Y - H:i');
+  $formats['short'] = $short_default;
+  $formats['medium'] = $config->get('medium');
+  $formats['long'] = $config->get('long');
 
   // For non-system types, get the default setting, otherwise use the short
   // format.
   foreach ($format_types as $type => $type_info) {
     if (!in_array($type, $system_types)) {
-      $formats['date_format_' . $type] = variable_get('date_format_' . $type, $short_default);
+      $default = $config->get($type);
+      $formats[$type] = !empty($default) ? $default : $short_default;
     }
   }
 
@@ -3686,7 +3689,7 @@ function system_time_zones($blank = NULL) {
     // reasons and should not be used, the list is filtered by a regular
     // expression.
     if (preg_match('!^((Africa|America|Antarctica|Arctic|Asia|Atlantic|Australia|Europe|Indian|Pacific)/|UTC$)!', $zone)) {
-      $zones[$zone] = t('@zone: @date', array('@zone' => t(str_replace('_', ' ', $zone)), '@date' => format_date(REQUEST_TIME, 'custom', variable_get('date_format_long', 'l, F j, Y - H:i') . ' O', $zone)));
+      $zones[$zone] = t('@zone: @date', array('@zone' => t(str_replace('_', ' ', $zone)), '@date' => format_date(REQUEST_TIME, 'custom', config('system.date_format_type')->get('long') . ' O', $zone)));
     }
   }
   // Sort the translated time zones alphabetically.
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php b/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php
index 3ff4daf..252049c 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserTimeZoneTest.php
@@ -28,7 +28,9 @@ class UserTimeZoneTest extends WebTestBase {
     // Setup date/time settings for Los Angeles time.
     variable_set('date_default_timezone', 'America/Los_Angeles');
     variable_set('configurable_timezones', 1);
-    variable_set('date_format_medium', 'Y-m-d H:i T');
+    config('system.date_format_type')
+      ->set('medium', 'Y-m-d H:i T')
+      ->save();
 
     // Create a user account and login.
     $web_user = $this->drupalCreateUser();