@Override
    public String toString() {
        return "DateTimeSettings{" +
                "dateTimePattern='" + dateTimePattern + '\'' +
                ", timeZone=" + timeZone +
                ", localZoneId='" + localZoneId + '\'' +
                ", referenceTime=" + referenceTime +
                '}';
    }
@return A copy of this but without the referenceTime.
stroom-query/stroom-query-api/src/main/java/stroom/query/api/DateTimeSettings.java