return err
	}
	// While AWS documentation mentions that the date specified
	// must be present in ISO 8601 format, in reality they allow
	// users to provide RFC 3339 compliant dates.
	retDate, err := amztime.ISO8601Parse(dateStr)
	if err != nil {
		return ErrInvalidRetentionDate
	}

	*rDate = RetentionDate{retDate}
	return nil
}

// MarshalXML encodes expiration date if it is non-zero and encodes