Java Utililty Methods Day of Week

if (date == null) {
    return null;
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 5);
return c.getTime();
...

Calendar c = Calendar.getInstance();
int weekDay = c.get(Calendar.DAY_OF_WEEK);
int days = dayOfWeek - weekDay;
if (days < 0) {
    days += 7;
c.add(Calendar.DAY_OF_YEAR, days);
c.set(Calendar.HOUR_OF_DAY, hourOfDay);
...

int seqWeek = 0;
int curDate = getDate(date);
int[][] month = getMonthDays(date);
for (int i = 0; i < 6; i++) {
    for (int j = 0; j < 7; j++) {
        if (month[i][j] != 0) {
            if (month[i][j] == curDate)
                seqWeek = i + 1;
...

Calendar c = Calendar.getInstance();
c.setTime(currDate);
c.setFirstDayOfWeek(Calendar.MONDAY);
return c.get(Calendar.WEEK_OF_MONTH);

Calendar c = Calendar.getInstance(Locale.US);
c.set(year, 1, 1, 0, 0, 0);
c.set(Calendar.WEEK_OF_YEAR, week);
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
c.add(Calendar.DAY_OF_YEAR, 1);
return c.getTime();

Description:Get start date of weeks specified by parameter weekNum beginning from the week

List<Date> result = new ArrayList<Date>();
Calendar calendar = Calendar.getInstance();
calendar.setTime(baseDate);
result.add(new Date(baseDate.getTime()));
for (int i = 0; i < weekNum - 1; i++) {
    calendar.add(Calendar.DAY_OF_YEAR, 7);
    result.add(calendar.getTime());
return result;

Calendar cal = getFirstSundayDateInYear(year);
cal.add(Calendar.DAY_OF_YEAR, (week - 1) * 7);
return cal.getTime();

Calendar sunday = getCalendar();
sunday.setTime(date);
sunday.setFirstDayOfWeek(FIRST_DAY_OF_WEEK);
sunday.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
return sunday.getTime();

Calendar c1 = Calendar.getInstance();
c1.setTime(early);
int week = c1.get(Calendar.DAY_OF_WEEK);
int firstw = -1 * (week - 1);
Date weekFirst = dayAdd(early, firstw);
return weekFirst;

return getCalendar(date).get(7);