Java Utililty Methods Day Count

long duration = getTimeCount(from, to, DATE_FORMAT.toPattern());
return (int) (duration / (1000 * 60 * 60 * 24));

return getDayCountWithFormatter(from, to, "yyyyMMdd");

SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
Date date = myFormatter.parse(yyyy_mm_dd_1);
Date mydate = myFormatter.parse(yyyy_mm_dd_2);
return (int) ((date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000));

Long days = 0L;
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
days = (sdf.parse(endDate).getTime() - sdf.parse(beginDate).getTime()) / (24 * 60 * 60 * 1000);
return days;

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
long day = 0;
try {
    long start_timeStamp = sdf.parse(start_time).getTime();
    long end_timeStamp = sdf.parse(end_time).getTime();
    day = (end_timeStamp - start_timeStamp) / (24 * 60 * 60 * 1000);
} catch (ParseException e) {
    e.printStackTrace();
...

if (d1.after(d2)) { 
    Calendar swap = d1;
    d1 = d2;
    d2 = swap;
int days = d2.get(Calendar.DAY_OF_YEAR) - d1.get(Calendar.DAY_OF_YEAR);
int y2 = d2.get(Calendar.YEAR);
if (d1.get(Calendar.YEAR) != y2) {
...

String start = params.get("start_date").toString();
String end = params.get("end_date").toString();
Calendar startCalendar = Calendar.getInstance();
Calendar endCalendar = Calendar.getInstance();
Date startDate = null;
Date endDate = null;
try {
    startDate = new SimpleDateFormat("yy-MM-dd").parse(start);
...

Date dtFrom = null;
Date dtEnd = null;
dtFrom = toDate(dateFrom, "yyyy-MM-dd");
dtEnd = toDate(dateEnd, "yyyy-MM-dd");
long begin = dtFrom.getTime();
long end = dtEnd.getTime();
long inter = end - begin;
if (inter < 0) {
...

DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
Date d1 = df.parse(strStartDate);
Date d2 = df.parse(strEndDate);
long diff = d2.getTime() - d1.getTime();
return diff / (1000 * 60 * 60 * 24);