code: public DateFuncSup nextMonth(int next) {
                  Calendar cal = Calendar.getInstance();
                  cal.setTime(date);
                  cal.add(Calendar.MONTH, next);
                  date.setTime(cal.getTimeInMillis());
                  return this;
          }
docs: set date to next months
  
  @param next count of next months to set to
  @return <code>this</code>