ActivityModel::getPruneDate PHP Метод

    private function getPruneDate()
    {
        if (!$this->pruneAfter) {
            return null;
        } else {
            $tz = new \DateTimeZone('UTC');
            $now = new DateTime('now', $tz);
            $test = new DateTime($this->pruneAfter, $tz);
            $interval = $test->diff($now);
            if ($interval->invert === 1) {
                return $now->add($interval);
            } else {
                return $test;
            }
        }
    }