chamilo / chamilo-lms

        $values = api_get_utc_datetime($timestamp);

        $values = str_replace(array(':', '-', ' '), '/', $values);

        list($y, $m, $d, $h, $n, $s) = split('/', $values);

        if ($m + $num > 12) {

            $y += floor($num / 12);

            $m += $num % 12;

        } else {

            $m += $num;

        }

        //date_default_timezone_set('UTC');

        // return mktime($h, $n, $s, $m, $d, $y);

        $result = api_strtotime($y.'-'.$m.'-'.$d.' '.$h.':'.$n.':'.$s, 'UTC');

            '/',

            date('Y/m/d/h/i/s', $timestamp)

        );

        if ($m + $num > 12) {

            $y += floor($num / 12);

            $m += $num % 12;

        } else {

            $m += $num;

        }

        return mktime($h, $n, $s, $m, $d, $y);

    }