TimeZone.php

diff --git a/TimeZone.php b/TimeZone.php
index 2330614..b32c0cd 100644 (file)
--- a/TimeZone.php
+++ b/TimeZone.php
@@ -109,7 +109,7 @@ class Pman_Core_TimeZone extends Pman
         return self::$timezones;
     }
 
-    function isValidTimeZone($tz) {
+    static function isValidTimeZone($tz) {
         try {
             new DateTimeZone($tz);
         }