code: private Date addDays(final Date date, final int days) {
          final Calendar cal = Calendar.getInstance();
          cal.setTime(date);
          cal.add(Calendar.DATE, days); //minus number would decrement the days
          return cal.getTime();
      }
docs: Create a new future Date from the specified Date.
  
  @param date The date to base the future date from
  @param days The number of dates to + offset
  @return a future date