public Date dateChange(Date in, boolean add) {
    Calendar c = Calendar.getInstance();
    c.setTimeInMillis(in.getTime());
    calendarChange(c, add);
    return new Date(c.getTimeInMillis());
  }
Add or subtract interval value to the specified date
hplsql/src/main/java/org/apache/hive/hplsql/Interval.java