code: public static DateTime calciteDateToJoda(final int date, final DateTimeZone timeZone)
    {
      return DateTimes.EPOCH.plusDays(date).withZoneRetainFields(timeZone);
    }
docs: The inverse of {@link #jodaToCalciteDate(DateTime, DateTimeZone)}.
  
  @param date     Calcite style date
  @param timeZone session time zone
  
  @return joda timestamp, with time zone set to the session time zone