public Long getReferenceTime() {
        return referenceTime;
    }
@param dateTimePattern The client date time pattern to use by default for formatting search results that contain
                       dates.
@param timeZone        The client timezone to use by default for formatting search results that contain dates.
@param localZoneId     The locale to use when formatting date values in the search results. The value is the
                       string form of a {@link java.time.ZoneId zoneId}
stroom-query/stroom-query-api/src/main/java/stroom/query/api/DateTimeSettings.java