@Override
  public void transientInit(Configuration conf) throws HiveException {
    super.transientInit(conf);
    if (timeZone == null) {
      String timeZoneStr = HiveConf.getVar(conf, HiveConf.ConfVars.HIVE_LOCAL_TIME_ZONE);
      timeZone = TimestampTZUtil.parseTimeZone(timeZoneStr);
    }
  }
Return Unix Timestamp.
Extends {@link VectorUDFTimestampFieldTimestamp}
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/VectorUDFUnixTimeStampTimestamp.java