diff --git a/core/includes/common.inc b/core/includes/common.inc
index 89a6c77..fe09862 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1943,30 +1943,29 @@ function format_date($timestamp, $type = 'system_medium', $format = '', $timezon
   if (empty($langcode)) {
     $langcode = language(LANGUAGE_TYPE_INTERFACE)->langcode;
   }
-  $settings = array('langcode' => $langcode);
 
   // Create a DrupalDateTime object from the timestamp and timezone.
-  $date_time = new DrupalDateTime($timestamp, $timezones[$timezone]);
+  $date = new DrupalDateTime($timestamp, $timezones[$timezone]);
 
   // Find the appropriate format type.
-  $key = $date_time->canUseIntl() ? DrupalDateTime::INTL : DrupalDateTime::PHP;
+  $key = $date->canUseIntl() ? DrupalDateTime::INTL : DrupalDateTime::PHP;
 
   // if we have a non-custom date format use the provided date format pattern.
   if ($type != 'custom') {
     $format = config('system.date')->get('formats.' . $type . '.pattern.' . $key);
   }
 
-  // Fall back to system_medium if a value was not found.
+  // Fall back to system_medium if a format was not found.
   if (empty($format)) {
     $format = config('system.date')->get('formats.system_medium.pattern.' . $key);
   }
 
-  if ($key == DrupalDateTime::INTL) {
-    $settings['format_string_type'] = $key;
-  }
-
-  // Call date_format().
-  return $date_time->format($format, $settings);
+  // Call $date->format().
+  $settings = array(
+    'langcode' => $langcode,
+    'format_string_type' => $key,
+  );
+  return $date->format($format, $settings);
 }
 
 /**
diff --git a/core/modules/system/config/system.date.yml b/core/modules/system/config/system.date.yml
index c2dfc78..a1b1120 100644
--- a/core/modules/system/config/system.date.yml
+++ b/core/modules/system/config/system.date.yml
@@ -30,7 +30,7 @@ formats:
     name: 'HTML Datetime'
     pattern:
       php: 'Y-m-d\TH:i:sO'
-      intl: 'yyyy-MM-dd'Tkk:mm:ssZZ'
+      intl: "yyyy-MM-dd'Tkk:mm:ssZZ"
     locked: 1
   html_date:
     name: 'HTML Date'
@@ -54,7 +54,7 @@ formats:
     name: 'HTML Week'
     pattern:
       php: 'Y-\WW'
-      intl: 'Y-'WW'
+      intl: "Y-'WW"
     locked: 1
   html_month:
     name: 'HTML Month'
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index 1f79f24..616528f 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -2868,8 +2868,8 @@ function system_date_format_localize_form($form, &$form_state, $langcode) {
  */
 function system_date_time_lookup($form, &$form_state) {
   $format = '';
-  if (!empty($form_state['values']['date_format'])) {
-    $format = t('Displayed as %date_format', array('%date_format' => format_date(REQUEST_TIME, 'custom', $form_state['values']['date_format'])));
+  if (!empty($form_state['values']['date_format_pattern'])) {
+    $format = t('Displayed as %date_format', array('%date_format' => format_date(REQUEST_TIME, 'custom', $form_state['values']['date_format_pattern'])));
   }
   // Return a command instead of a string, since the Ajax framework
   // automatically prepends an additional empty DIV element for a string, which