Java Utililty Methods Date Compare

DateFormat format = DateFormat.getDateInstance(DateFormat.MEDIUM);
String datesb1 = format.format(date);
String datesb2 = format.format(otherdate);
return datesb1.equals(datesb2);

Calendar c = Calendar.getInstance();
c.clear();
Date date2 = c.getTime();
long quot;
quot = date1.getTime() - date2.getTime();
quot = quot / 1000 / 60 / 60 / 24;
int day = new Long(quot).intValue();
return day;
...

Calendar calendar1 = Calendar.getInstance();
Calendar calendar2 = Calendar.getInstance();
calendar1.setTime(date1);
calendar2.setTime(date2);
calendar1.set(Calendar.SECOND, 0);
calendar2.set(Calendar.SECOND, 0);
calendar1.set(Calendar.MILLISECOND, 0);
calendar2.set(Calendar.MILLISECOND, 0);
...

DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
try {
    Date dt1 = df.parse(df.format(DATE1));
    Date dt2 = df.parse(df.format(DATE2));
    if (dt1.getTime() > dt2.getTime()) {
        return 1;
    } else if (dt1.getTime() < dt2.getTime()) {
        return -1;
...

if (date1 == null || date2 == null)
    return null;
java.util.Calendar c = java.util.Calendar.getInstance();
c.setTime(date1);
long d1 = c.getTimeInMillis();
c.setTime(date2);
long d2 = c.getTimeInMillis();
long tmp = (d1 > d2) ? (d1 - d2) : (d2 - d1);
...

long due = date1.getTime() + 0 * 24 * 60 * 60 * 1000;
long due2 = date2.getTime() + 0 * 24 * 60 * 60 * 1000;
if (due == due2) {
    return 0;
} else if (due > due2) {
    return 1;
} else
    return -1;
...

if (date1 == null || date2 == null)
    return -1;
Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
cal1.setTime(date1);
cal2.setTime(date2);
return cal1.compareTo(cal2);

Calendar c1 = Calendar.getInstance();
c1.setTime(date1);
Calendar c2 = Calendar.getInstance();
c2.setTime(date2);
if (c1.get(Calendar.YEAR) != c2.get(Calendar.YEAR))
    return c1.get(Calendar.YEAR) - c2.get(Calendar.YEAR);
if (c1.get(Calendar.MONTH) != c2.get(Calendar.MONTH))
    return c1.get(Calendar.MONTH) - c2.get(Calendar.MONTH);
...

Calendar c1 = Calendar.getInstance();
c1.setTime(date1);
Calendar c2 = Calendar.getInstance();
c2.setTime(date2);
return compareDate(c1, c2);

String d1 = date2Str(date1, pattern);
String d2 = date2Str(date2, pattern);
return d1.compareTo(d2);