protected function validateCreatedReview()
    {
        $field = 'created';
        $value = $this->getSubmitted($field);

        if (!isset($value)) {
            $this->unsetSubmitted($field);
            return null;
        }

        $timestamp = strtotime($value);

        if (empty($timestamp)) {
            $this->setErrorInvalid($field, $this->translation->text('Created'));
            return false;
        }

        $this->setSubmitted('created', $timestamp);
        return true;
    }