Java Utililty Methods Week Day

return new Date().getTime() - 7 * 24 * 60 * 60 * 1000;

Date date = Calendar.getInstance().getTime();
String sDate = convDateToString(date, "MM");
return sDate;

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat format2 = new SimpleDateFormat("yyyyMMdd");
Date d = null;
try {
    d = format.parse(date);
} catch (Exception e) {
    e.printStackTrace();
Calendar cal = Calendar.getInstance();
cal.setTime(d);
int days = cal.get(Calendar.DAY_OF_WEEK);
if (days == 1) {
    days = 1;
    String preMonday = getPreviousMonday(d, days);
    System.out.println("preMonday" + preMonday);
    return preMonday;
} else {
    cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
    return format2.format(cal.getTime());

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date d = null;
try {
    d = format.parse(date);
} catch (Exception e) {
    e.printStackTrace();
Calendar cal = Calendar.getInstance();
...

Calendar cal = Calendar.getInstance();
cal.setTime(date);
while (cal.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
    cal.add(Calendar.DATE, 1);
return cal.getTime();

Calendar c = Calendar.getInstance();
int day_of_week = c.get(Calendar.DAY_OF_WEEK) - 1;
if (day_of_week == 0)
    day_of_week = 7;
c.add(Calendar.DATE, -day_of_week + 1);
return new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());

Calendar calendar = Calendar.getInstance();
calendar.setTime(new java.util.Date(date.getTime() + 24 * 60 * 60 * 1000));
if (calendar.get(Calendar.DAY_OF_WEEK) == 1)
    return 7;
else
    return calendar.get(Calendar.DAY_OF_WEEK) - 1;

Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DAY_OF_WEEK, -1);
Date preTime = calendar.getTime();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
return formatter.format(preTime);

return getDay(date, startOfWeek, -1);

Date d = strToDtSimpleFormat(date);
Calendar cal = Calendar.getInstance();
cal.setTime(d);
cal.add(Calendar.WEEK_OF_YEAR, -1);
cal.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);
return dateFormat(cal.getTime());