cdm/src/main/java/ucar/nc2/ft2/coverage/remote/CdmrfWriter.java
CdmrFeatureProto.CalendarDateRange.Builder encodeDateRange(CalendarDateRange dateRange) {
    CdmrFeatureProto.CalendarDateRange.Builder builder = CdmrFeatureProto.CalendarDateRange.newBuilder();

    builder.setStart(dateRange.getStart().getMillis());
    builder.setEnd(dateRange.getEnd().getMillis());
    Calendar cal = dateRange.getStart().getCalendar();
    builder.setCalendar(convertCalendar(cal));
    return builder;
  }
CdmrFeatureProto.CalendarDateRange.Builder encodeDateRange(CalendarDateRange dateRange) {
    CdmrFeatureProto.CalendarDateRange.Builder builder = CdmrFeatureProto.CalendarDateRange.newBuilder();

    builder.setStart(dateRange.getStart().getMillis());
    builder.setEnd(dateRange.getEnd().getMillis());
    Calendar cal = dateRange.getStart().getCalendar();
    builder.setCalendar(convertCalendar(cal));
    return builder;
  }
/* message CalendarDateRange {
required int64 start = 1;
required int64 end = 2;
required int32 calendar = 3; // calendar ordinal
}