public static long convertTime(long original,
                                 boolean fromProleptic,
                                 boolean toProleptic) {
    if (fromProleptic != toProleptic) {
      return toProleptic
          ? convertTimeToProleptic(original)
          : convertTimeToHybrid(original);
    } else {
      return original;
    }
  }
Convert an epoch day from the proleptic Gregorian calendar to the hybrid
Julian/Gregorian.
@param proleptic day of epoch in the proleptic Gregorian
@return day of epoch in the hybrid Julian/Gregorian
storage-api/src/java/org/apache/hadoop/hive/common/type/CalendarUtils.java