remove this file in your site if present: dataroot/temp/olson.txt remove this file in your site if present: dataroot/temp/timezone.txt disable network access, so http://download.moodle.org/timezone/ cannot be accesed go to Admin -> Location -> Update timezones press the continue button, so the local lib/timezone.txt will be loaded TEST: With debugging enabled, you should get one message like "cURL request for "http://download.moodle.org/timezone/" failed". Perfect, that means you disabled network access ok. TEST: ignoring the previous warning, the load ends without any PHP notice/warning/error. TEST: The page shows this info: "2184 entries imported from YOUR_MOODLE_BASEDIR/lib/timezone.txt". 2184 is the important bit. And also that the load has happened from that directory. Go to admin -> development -> unit tests TEST: Run the lib/simpletest/testmoodlelib.php tests. Process should end with "328 passes, 0 fails and 0 exceptions." (or, alternatively, if there are some tests failing, none of them are related to date/time functions). POST-TEST: 48 hours later, with network access enabled, load the timezones again, it should show the same number of timezones (2184) but loaded from http://download.moodle.org/timezone/