@Test
  public void convertDatetimeStrToLongTest2() {
    zoneOffset = ZoneOffset.UTC;
    zoneId = ZoneId.of("Etc/UTC");
    delta = 8 * 3600000;
    testConvertDatetimeStrToLongWithoutMS(zoneOffset, zoneId, timestamp - 689 + delta);
    testConvertDatetimeStrToLongWithMS(zoneOffset, zoneId, timestamp + delta);
    testConvertDatetimeStrToLongWithMS2(zoneOffset, zoneId, timestamp - 9 + delta);
  }
Test convertDatetimeStrToLong() method with different time precision.
iotdb-core/datanode/src/test/java/org/apache/iotdb/db/utils/DateTimeUtilsTest.java