public static function monthize($days)
    {
        $now = new \DateTime();
        $end = new \DateTime();

        $duration = new \DateInterval("P{$days}D");

        $diff = $end->add($duration)->diff($now);

        // handle years
        if ($diff->y > 0) {
            $diff->m += 12 * $diff->y;
        }

        return $diff->m;
    }