Calculate the number of days between two dates in Java

See English answers > Android / Java – date difference in days17

public static long getNoOfDaysBtwnDates(String expiryDate) {
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
    Date expDate = null;
    long diff = 0;
    long noOfDays = 0;
    try {

        expDate = formatter.parse(expiryDate);
        //logger.info("Expiry Date is " + expDate);
       // logger.info(formatter.format(expDate));

        Date createdDate = new Date();
        diff = expDate.getTime() - createdDate.getTime();
        noOfDays = TimeUnit.DAYS.convert(diff,TimeUnit.MILLISECONDS);
        long a = TimeUnit.DAYS.toDays(noOfDays);
       // logger.info("No of Day after difference are - " + TimeUnit.DAYS.convert(diff,TimeUnit.MILLISECONDS));
        System.out.println(a);
        System.out.println(noOfDays);

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

    return noOfDays;
}

The expiration date is June 30, 2016, and the current date is June 27, 2016

Solution

The reason is that you did not subtract two dates using the same time format

Use the calendar class to change the time of the date to 00:00:00, and you will get the exact difference of several days

Date createdDate = new Date();
Calendar time  = Calendar.getInstance();
time.set(Calendar.HOUR_OF_DAY,0);
time.set(Calendar.MINUTE,0);
time.set(Calendar.SECOND,0);
time.set(Calendar.MILLISECOND,0);
createdDate = time.getTime();

More explanations in Jim Garrison's answer