Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.537.2.14
diff -u -r1.537.2.14 common.inc
--- includes/common.inc	18 Oct 2006 20:14:42 -0000	1.537.2.14
+++ includes/common.inc	3 Nov 2006 05:53:39 -0000
@@ -891,18 +891,22 @@
  *   A translated date string in the requested format.
  */
 function format_date($timestamp, $type = 'medium', $format = '', $timezone = NULL) {
+  global $user;
+
   if (!isset($timezone)) {
-    global $user;
     if (variable_get('configurable_timezones', 1) && $user->uid && strlen($user->timezone)) {
       $timezone = $user->timezone;
+      $timestamp += $timezone;
     }
     else {
       $timezone = variable_get('date_default_timezone', 0);
+      $timestamp += $timezone;
+      if (variable_get('daylight_saving_time', 0) && drupal_is_dst($timestamp)) {
+        $timestamp += 3600;
+      }
     }
   }
 
-  $timestamp += $timezone;
-
   switch ($type) {
     case 'small':
       $format = variable_get('date_format_short', 'm/d/Y - H:i');
@@ -1470,3 +1474,68 @@
     }
   }
 }
+
+
+/**
+ * Check if time is in Daylight Savings Time
+ *
+ * @param
+ *   $timestamp a timestamp
+ * @return
+ *   0 or 1
+ */
+function drupal_is_dst($timestamp) {
+  $year = date('Y', $timestamp);
+  $timezone = variable_get('date_default_timezone', 0);
+
+  // Information on Daylight Saving time was obtained from http://webexhibits.org/daylightsaving/g.html
+  switch (variable_get('daylight_saving_time', 0)) {
+    case 0:
+      return 0;
+    case 1: // EU and other European countries
+      // start of DST (last Sunday in March 1 am GMT)
+      $dststart = strtotime("-1 week sunday GMT", strtotime("1 april $year GMT")) + 3600;
+      // end of DST in Europe (last Sunday in October 1 am GMT)
+      $dstend = strtotime("-1 week sunday GMT", strtotime("1 november $year GMT")) + 3600;
+      break;
+    case 2: // Russian Federation
+      // start of DST (last Sunday in March 2 am local time)
+      $dststart = strtotime("-1 week sunday GMT", strtotime("1 april $year GMT")) + 7200 + $timezone;
+      // end of DST (last Sunday in October 2 am local time)
+      $dstend = strtotime("-1 week sunday GMT", strtotime("1 november $year GMT")) + 7200 + $timezone;
+      break;
+    case 3: // Northern America (where applicable)
+      // start of DST  (where applicable) (first Sunday in April 2 am local time)
+      $dststart = strtotime("1 week sunday GMT", strtotime("1 april $year GMT")) + 7200 + $timezone;
+      // end of DST (where applicable) (last Sunday in October 2 am local time)
+      $dstend = strtotime("-1 week sunday GMT", strtotime("1 november $year GMT")) + 7200 + $timezone;
+      break;
+    case 4: // Australia
+      // start of DST  (last Sunday in October at 2am)
+      $dststart = strtotime("-1 week sunday GMT", strtotime("1 november $year GMT")) + 7200 + $timezone;
+      // end of DST (last Sunday in March at 2am)
+      $dstend = strtotime("-1 week sunday GMT", strtotime("1 april $year GMT")) + 7200 + $timezone;
+      if ($dstend < $timestamp) {
+        $dstend = strtotime("+1 year", $dstend);
+      }
+      elseif ($dststart > $timestamp) {
+        $dststart = strtotime("-1 year", $dststart);
+      }
+      break;
+    case 5: // New Zealand
+      // start of DST  (last Sunday in October)
+      $dststart = strtotime("-1 week sunday GMT", strtotime("1 november $year GMT")) + 7200 + $timezone;
+      // end of DST (third Sunday in March)
+      $dstend = strtotime("3 week sunday GMT", strtotime("1 march $year GMT")) + 7200 + $timezone;
+      if ($dstend < $timestamp) {
+        $dstend = strtotime("+1 year", $dstend);
+      }
+      elseif ($dststart > $timestamp) {
+        $dststart = strtotime("-1 year", $dststart);
+      }
+      break;
+  }
+
+  return ($dststart <= $timestamp && $timestamp <= $dstend);
+}
+
Index: modules/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/Attic/node.module,v
retrieving revision 1.641.2.17
diff -u -r1.641.2.17 node.module
--- modules/node.module	18 Oct 2006 20:14:42 -0000	1.641.2.17
+++ modules/node.module	3 Nov 2006 05:53:41 -0000
@@ -1605,6 +1605,12 @@
 
     if (!isset($node->date)) {
       $node->date = format_date($node->created, 'custom', 'Y-m-d H:i:s O');
+      if (!variable_get('configurable_timezones', 1)) {
+        if (drupal_is_dst($node->created)) {
+          $node->created -= 3600;
+          $node->date = format_date($node->created, 'custom', 'Y-m-d H:i:s O');
+        }
+      }
     }
   }
   node_invoke($node, 'prepare');
Index: modules/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/Attic/system.module,v
retrieving revision 1.320.2.12
diff -u -r1.320.2.12 system.module
--- modules/system.module	18 Oct 2006 20:37:08 -0000	1.320.2.12
+++ modules/system.module	3 Nov 2006 05:53:43 -0000
@@ -399,6 +399,15 @@
   // Date settings:
   $zones = _system_zonelist();
 
+  // Daylight saving time settings
+  $dst = array(t('None'),
+               t('EU and other European countries'),
+               t('Russian Federation'),
+               t('Northern America (where applicable)'),
+               t('Australia (where applicable)'),
+               t('New Zealand')
+              );
+
   // 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',
            'd.m.Y - H:i', 'm/d/Y - g:ia', 'd/m/Y - g:ia', 'Y/m/d - g:ia',
@@ -428,6 +437,11 @@
     '#options' => $zones, '#description' => t('Select the default site time zone.')
   );
 
+  $form['dates']['daylight_saving_time'] = array(
+    '#type' => 'radios', '#title' => t('Daylight saving time '), '#default_value' => variable_get('daylight_saving_time', 0), '#options' => $dst,
+    '#description' => t('Select the Daylight saving time setting (DST) appropriate for your site. Takes only effect if configurable time zones are disabled. If chosing a setting here, make sure you set your default time zone to standard time.')
+  );
+
   $form['dates']['configurable_timezones'] = array(
     '#type' => 'radios', '#title' => t('Configurable time zones'), '#default_value' => variable_get('configurable_timezones', 1), '#options' => array(t('Disabled'), t('Enabled')),
     '#description' => t('Enable or disable user-configurable time zones.  When enabled, users can set their own time zone and dates will be updated accordingly.')