switch ($tz) {
    case 's':
        $tzoffset  = 0;
        $tzdisp    = ($serverTZ >= 0 ? '+' : '-') . sprintf('%02d:%02d', abs($serverTZ), abs($serverTZ) * 60 % 60);
        $tzoptions = str_replace("'s'>", "'s' selected>", $tzoptions);