public static LocalDate convertToLocalDate(long timestamp, ZoneId zoneId) {
    timestamp = CAST_TIMESTAMP_TO_MS.apply(timestamp);
    return Instant.ofEpochMilli(timestamp).atZone(zoneId).toLocalDate();
  }
convert duration string to millisecond, microsecond or nanosecond.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/DateTimeUtils.java