public void set(Date d) {
    if (d == null) {
      daysSinceEpoch = 0;
      return;
    }

    set(dateToDays(d));
  }
Set the DateWritable based on the year/month/day of the date in the local timezone.
@param d Date value
storage-api/src/java/org/apache/hadoop/hive/serde2/io/DateWritable.java