diff --git a/includes/form.inc b/includes/form.inc
index 4747ba971a1487e4a1cb7d774c1f114ba782182c..1a7863e55994b05e56013c8843848a63f76df1cb 100644
--- a/includes/form.inc
+++ b/includes/form.inc
@@ -1036,7 +1036,7 @@ function expand_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');
+  $format = variable_get('date_format_short', 'm/d/Y - H:i');
   $sort = array();
   $sort['day'] = max(strpos($format, 'd'), strpos($format, 'j'));
   $sort['month'] = max(strpos($format, 'm'), strpos($format, 'M'));
diff --git a/modules/aggregator/aggregator.module b/modules/aggregator/aggregator.module
index a5ec9b18cb9511a555b8b318ec423f8a11557b92..d5cf06263706a0ddb83ab0f3ff1d4914d0118de9 100644
--- a/modules/aggregator/aggregator.module
+++ b/modules/aggregator/aggregator.module
@@ -1368,7 +1368,7 @@ function theme_aggregator_page_item($item) {
     $source_date = t('%ago ago', array('%ago' => format_interval(time() - $item->timestamp)));
   }
   else {
-    $source_date = format_date($item->timestamp, 'custom', variable_get('date_format_medium', 'D, Y-m-d H:i'));
+    $source_date = format_date($item->timestamp, 'custom', variable_get('date_format_medium', 'D, m/d/Y - H:i'));
   }
 
   $output .= "<div class=\"feed-item\">\n";
diff --git a/modules/system/system.module b/modules/system/system.module
index b89c5adc2c7f5ae66a52d0dc6de350dad97e290f..ac6ae856bb04393a35814b7bc47d90ddf7abd8b6 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -722,7 +722,7 @@ function system_date_time_settings() {
   $zones = _system_zonelist();
 
   // Date settings: possible date formats
-  $dateshort = array('Y-m-d H:i','m/d/Y - H:i', 'd/m/Y - H:i', 'Y/m/d - H:i',
+  $dateshort = array('Y-m-d H:i', 'm/d/Y - H:i', 'd/m/Y - H:i', 'Y/m/d - H:i',
            'd.m.Y - H:i', 'm/d/Y - g:ia', 'd/m/Y - g:ia', 'Y/m/d - g:ia',
            'M j Y - H:i', 'j M Y - H:i', 'Y M j - H:i',
            'M j Y - g:ia', 'j M Y - g:ia', 'Y M j - g:ia');
@@ -763,7 +763,7 @@ function system_date_time_settings() {
   $form['date_format_short'] = array(
     '#type' => 'select',
     '#title' => t('Short date format'),
-    '#default_value' => variable_get('date_format_short', $dateshort[0]),
+    '#default_value' => variable_get('date_format_short', $dateshort[1]),
     '#options' => $dateshortchoices,
     '#description' => t('The short format of date display.')
   );
@@ -771,7 +771,7 @@ function system_date_time_settings() {
   $form['date_format_medium'] = array(
     '#type' => 'select',
     '#title' => t('Medium date format'),
-    '#default_value' => variable_get('date_format_medium', $datemedium[0]),
+    '#default_value' => variable_get('date_format_medium', $datemedium[1]),
     '#options' => $datemediumchoices,
     '#description' => t('The medium sized date display.')
   );