Java Utililty Methods Month Day

Calendar sysDate = new GregorianCalendar();
sysDate.setTime(date);
sysDate.add(Calendar.MONTH, months);
sysDate.add(Calendar.DAY_OF_MONTH, days);
return sysDate.getTime();

for (int i = 0; i < monthInterval; i++) {
    c.set(Calendar.DAY_OF_MONTH, 1);
    c.add(Calendar.DATE, 33);
    c.set(Calendar.DAY_OF_MONTH, dayOfMonth);
    if (c.get(Calendar.DAY_OF_MONTH) != dayOfMonth) {
        c.set(Calendar.DAY_OF_MONTH, 1);
        c.add(Calendar.DAY_OF_MONTH, -1);

int[] daysInMonths = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
daysInMonths[1] += c.isLeapYear(c.get(GregorianCalendar.YEAR)) ? 1 : 0;
return daysInMonths[c.get(GregorianCalendar.MONTH)];

Calendar c = Calendar.getInstance();
c.setTime(date);
c.set(Calendar.DAY_OF_MONTH, 1);
return c.getTime();

Calendar cal = calendar(date);
cal.set(Calendar.DAY_OF_MONTH, 1);
cal.set(Calendar.HOUR, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
return cal.getTime();

try {
    Date date = dd.parse(dateTime);
    Calendar now = Calendar.getInstance();
    now.setTime(date);
    int year = now.get(Calendar.YEAR);
    int month = now.get(Calendar.MONTH) - num;
    int day = now.get(Calendar.DAY_OF_MONTH);
    now.set(year, month, day);
...

Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);

Calendar cal = Calendar.getInstance();
Date d = new Date();
cal.setTime(d);
cal.set(Calendar.DATE, 1);
return dateFormat(cal.getTime());

Calendar c = new GregorianCalendar();
c.setTime(getCurrentDate());
return c.get(Calendar.DAY_OF_MONTH);

String current = getCurrentStringDate();
return current.substring(0, 7) + "-01";