util.php

<?php

// from http://php.net/manual/de/function.date-default-timezone-set.php#113864
function setTimezone($default) {
    $timezone = "";
    
    // On many systems (Mac, for instance) "/etc/localtime" is a symlink
    // to the file with the timezone info
    if (is_link("/etc/localtime")) {
        
        // If it is, that file's name is actually the "Olsen" format timezone
        $filename = readlink("/etc/localtime");
        
        $pos = strpos($filename, "zoneinfo");
        if ($pos) {
            // When it is, it's in the "/usr/share/zoneinfo/" folder
            $timezone = substr($filename, $pos + strlen("zoneinfo/"));
        } else {
            // If not, bail
            $timezone = $default;
        }
    }
    else {
        // On other systems, like Ubuntu, there's file with the Olsen time
        // right inside it.
        $timezone = file_get_contents("/etc/timezone");
        if (!strlen($timezone)) {
            $timezone = $default;
        }
    }
    date_default_timezone_set($timezone);
}

?>