code: public static Date addDays(Date date, int iDays) {
      Calendar dateTime = dateToCalendar(date);
      dateTime.add(Calendar.DATE, iDays);
      return dateTime.getTime();
    }
docs: Adds the specified (signed) amount of days to the given date. For
  example, to subtract 5 days from the current date, you can
  achieve it by calling: <code>addDays(Date, -5)</code>.
  
  @param date  The time.
  @param iDays The amount of days to add.
  
  @return A new date with the days added.