diff --git a/program/include/main.inc b/program/include/main.inc
index f6e2ca206..148c2bd5c 100644
--- a/program/include/main.inc
+++ b/program/include/main.inc
@@ -1072,7 +1072,7 @@ function format_date($date, $format=NULL, $convert=true)
   try {
     // convert to the right timezone
     $stz = date_default_timezone_get();
-    $tz = new DateTimeZone($convert ? $RCMAIL->config->get('timezones') : 'GMT');
+    $tz = new DateTimeZone($convert ? $RCMAIL->config->get('timezone') : 'GMT');
     $date->setTimezone($tz);
     date_default_timezone_set($tz->getName());
 
diff --git a/program/include/rcube_config.php b/program/include/rcube_config.php
index e16395711..038336480 100644
--- a/program/include/rcube_config.php
+++ b/program/include/rcube_config.php
@@ -254,9 +254,13 @@ class rcube_config
      */
     public function get_timezone()
     {
-      if ($this->get('timezone')) {
-        $tz = new DateTimeZone($this->get('timezone'));
-        return $tz->getOffset(new DateTime('now')) / 3600;
+      if ($tz = $this->get('timezone')) {
+        try {
+          $tz = new DateTimeZone($tz);
+          return $tz->getOffset(new DateTime('now')) / 3600;
+        }
+        catch (Exception $e) {
+        }
       }
 
       return 0;