public static long unixDateFloor(TimeUnitRange range, long date) {
    return julianDateFloor(range, (int) date + EPOCH_JULIAN, true);
  }
Appends year-month-day to a buffer; assumes they are valid.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/util/DateTimeUtils.java