1 files changed, 16 insertions, 1 deletions
diff --git a/program/include/rcube_config.php b/program/include/rcube_config.php
index b9fd95578..bbc3e9c6e 100644
--- a/program/include/rcube_config.php
+++ b/program/include/rcube_config.php
@@ -43,6 +43,8 @@ class rcube_config
         'mail_pagesize'        => 'pagesize',
         'addressbook_pagesize' => 'pagesize',
         'reply_mode'           => 'top_posting',
+        'refresh_interval'     => 'keep_alive',
+        'min_refresh_interval' => 'min_keep_alive',
     );
 
 
@@ -412,7 +414,20 @@ class rcube_config
      */
     private function client_timezone()
     {
-        return isset($_SESSION['timezone']) && ($ctz = timezone_name_from_abbr("", $_SESSION['timezone'] * 3600, 0)) ? $ctz : date_default_timezone_get();
+        if (isset($_SESSION['timezone']) && is_numeric($_SESSION['timezone'])
+              && ($ctz = timezone_name_from_abbr("", $_SESSION['timezone'] * 3600, 0))) {
+            return $ctz;
+        }
+        else if (!empty($_SESSION['timezone'])) {
+            try {
+                $tz = timezone_open($_SESSION['timezone']);
+                return $tz->getName();
+            }
+            catch (Exception $e) { /* gracefully ignore */ }
+        }
+
+        // fallback to server's timezone
+        return date_default_timezone_get();
     }
 
 }