Fix a bug in the conversion of int types to timestamps.

java/tsfile/src/main/java/org/apache/tsfile/utils/DateUtils.java

@@ -21,6 +21,8 @@
 
 import java.sql.Date;
 import java.time.LocalDate;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeParseException;
 
@@ -65,6 +67,7 @@ public static Integer parseDateExpressionToInt(LocalDate localDate) {
         + localDate.getDayOfMonth();
   }
 
+  // Do not use this method to get a timestamp, use parseIntToTimestamp instead.
   public static Date parseIntToDate(int date) {
     return new Date(date / 10000 - 1900, (date / 100) % 100 - 1, date % 100);
   }
@@ -76,4 +79,10 @@ public static LocalDate parseIntToLocalDate(int date) {
       throw new DateTimeParseException("Invalid date format.", "", 0);
     }
   }
+
+  public static long parseIntToTimestamp(int date, ZoneId zoneId) {
+    return ZonedDateTime.of(date / 10000, (date / 100) % 100, date % 100, 0, 0, 0, 0, zoneId)
+        .toInstant()
+        .toEpochMilli();
+  }
 }