switch ($status_type) {
            case 'INITIAL_BUY':
            case 'DID_RECOVER':
            case 'RENEWAL':
            case 'INTERACTIVE_RENEWAL':
            case 'DID_CHANGE_RENEWAL_STATUS':
                return 'expires_date_ms';
                break;
            case 'CANCEL':
                return 'cancellation_date_ms';
                break;
            case 'DID_FAIL_TO_RENEW':
                return '';
                break;
        }