Java Utililty Methods Month of Year

Calendar c = Calendar.getInstance();
DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
c.setTime(new Date());
c.add(Calendar.DATE, month);
Date d2 = c.getTime();
String s = df.format(d2);
return s;

String pattern = "yyyy-MM-dd";
Calendar cd = Calendar.getInstance();
cd.add(Calendar.MONTH, 1);
String newTime = String.valueOf(cd.get(Calendar.YEAR)) + "-" + String.valueOf(cd.get(Calendar.MONTH) + 1)
        + "-" + String.valueOf(cd.get(Calendar.DAY_OF_MONTH));
return convertStringToDate(newTime, pattern);

DateFormat aFmt = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = (Calendar) aCal.clone();
cal.add(Calendar.MONTH, 1);
return aFmt.format(cal.getTime());

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
Calendar temp = Calendar.getInstance();
temp.setTime(nowdate);
int oldMonth = temp.get(Calendar.MONTH);
int newMonth = oldMonth + delay;
int oldYear = temp.get(Calendar.YEAR);
int i, j;
if (newMonth > 12) {
...

Calendar cal = Calendar.getInstance();
Date dt = strToDtSimpleFormat(date);
cal.setTime(dt);
cal.add(Calendar.MONTH, 1);
cal.set(Calendar.DATE, 1);
return dateFormat(cal.getTime());

if (day == null)
    return null;
Calendar calendar = Calendar.getInstance();
calendar.setTime(day);
int month = calendar.get(Calendar.MONTH);
calendar.set(Calendar.MONTH, month + 1);
calendar.set(Calendar.DAY_OF_MONTH, 1);
String datefor = format(calendar.getTime(), "yyyy-MM-dd");
...

Date date = getDateFromString(nowdate, inFormat);
Calendar cl = Calendar.getInstance();
cl.setTime(date);
cl.set(2, cl.get(2) + 1);
cl.set(5, 1);
date = cl.getTime();
return getFormatTimeString(date, outFormat);

SimpleDateFormat format = new SimpleDateFormat(year_month_pattern);
Calendar calendar = Calendar.getInstance();
try {
    calendar.setTime(format.parse(yearMonth));
} catch (ParseException e) {
    e.printStackTrace();
calendar.add(Calendar.MONTH, 1);
...

Calendar cal = calendarForFirstDayOf(month, year);
return cal.getActualMaximum(Calendar.DAY_OF_MONTH);

Calendar calendar = new GregorianCalendar(year, month, 1);
return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);