java code for different date formats

public Long timeDifference(String weboutput) {
    try {
        Calendar calendar = GregorianCalendar.getInstance();
        Calendar today = new GregorianCalendar();
        Date inputTime;
        if (weboutput.length() <= 10) { // for data fetched for current date.
            DateFormat formatter = new SimpleDateFormat("hh:mm:ss a", Locale.US);
            inputTime = formatter.parse(weboutput);
            calendar.setTime(inputTime);
            int hour = calendar.get(Calendar.HOUR);
            int minute = calendar.get(Calendar.MINUTE);
            int second = calendar.get(Calendar.SECOND);
            today.setTime(new Date());
            today.set(Calendar.HOUR, hour);
            today.set(Calendar.MINUTE, minute);
            today.set(Calendar.SECOND, second);
        } else {
            if (weboutput.length() <= 15) { // for data for earlier date in same year or month.
                DateFormat formatter = new SimpleDateFormat("MMM dd hh:mm a", Locale.US);
                inputTime = formatter.parse(weboutput);
                calendar.setTime(inputTime);
                int hour = calendar.get(Calendar.HOUR);
                int minute = calendar.get(Calendar.MINUTE);
                int month = calendar.get(Calendar.MONTH);
                int date = calendar.get(Calendar.DATE);
                today.setTime(new Date());
                today.set(Calendar.HOUR, hour);
                today.set(Calendar.MINUTE, minute);
                today.set(Calendar.MONTH, month);
                today.set(Calendar.DATE, date);
            } else { // for data with different year.
                DateFormat formatter = new SimpleDateFormat("MMM dd, yyyy hh:mm:ss a", Locale.US);
                inputTime = formatter.parse(weboutput);
                calendar.setTime(inputTime);
                int hour = calendar.get(Calendar.HOUR);
                int minute = calendar.get(Calendar.MINUTE);
                int second = calendar.get(Calendar.SECOND);
                int month = calendar.get(Calendar.MONTH);
                int date = calendar.get(Calendar.DATE);
                int year = calendar.get(Calendar.YEAR);
                today.setTime(new Date());
                today.set(Calendar.HOUR, hour);
                today.set(Calendar.MINUTE, minute);
                today.set(Calendar.SECOND, second);
                today.set(Calendar.YEAR, year);
                today.set(Calendar.MONTH, month);
                today.set(Calendar.DATE, date);
            }
        }
        Date retrivedDate = today.getTime();
        Calendar cal = Calendar.getInstance();
        Date currentDate = cal.getTime();
        difference = currentDate.getTime() - retrivedDate.getTime();
        System.out.println(retrivedDate);
        System.out.println(currentDate);
        System.out.println(difference);

    } catch (ParseException e) {
        e.printStackTrace();
    }
    return difference;
}

public boolean alarmValue(Long alarmTime) {
    if (alarmTime <= 1800000) // change this value for Alarm duration, currently 30 min = 30* 60 s = 1800 * 1000 ms = 1800000 ms.
        return false;
    else
        return true;
}