DateFormat

DateFormat SLAH = new SimpleDateFormat("yyyy-MM-dd",Locale.US);

public static Date addDays(Date date, int days){
java.util.Calendar ca = Calendar.getInstance();
ca.setTime(date);
ca.add(Calendar.DAY_OF_YEAR,days);
return ca.getTime();
}

SLAH.format(addDays(date,days));