Calculate date/time difference in java [duplicate]

Question

This question already has an answer here:

• How to convert Milliseconds to “X mins, x seconds” in Java? 25 answers

I want to calculate difference between 2 dates in hours/minutes/seconds.

I have a slight problem with my code here it is :

String dateStart = "11/03/14 09:29:58";
String dateStop = "11/03/14 09:33:43";

// Custom date format
SimpleDateFormat format = new SimpleDateFormat("yy/MM/dd HH:mm:ss");  

Date d1 = null;
Date d2 = null;
try {
    d1 = format.parse(dateStart);
    d2 = format.parse(dateStop);
} catch (ParseException e) {
    e.printStackTrace();
}    

// Get msec from each, and subtract.
long diff = d2.getTime() - d1.getTime();
long diffSeconds = diff / 1000;         
long diffMinutes = diff / (60 * 1000);         
long diffHours = diff / (60 * 60 * 1000);                      
System.out.println("Time in seconds: " + diffSeconds + " seconds.");         
System.out.println("Time in minutes: " + diffMinutes + " minutes.");         
System.out.println("Time in hours: " + diffHours + " hours."); 

This should produce :

Time in seconds: 45 seconds.
Time in minutes: 3 minutes.
Time in hours: 0 hours.

However I get this result :

Time in seconds: 225 seconds.
Time in minutes: 3 minutes.
Time in hours: 0 hours.

Can anyone see what I'm doing wrong here ?

Answer 1

Here is my code.

import java.util.Date;

// to calculate difference between two days
public class DateDifference {

// to calculate difference between two dates in milliseconds
public long getDateDiffInMsec(Date da, Date db) {
    long diffMSec = 0;
    diffMSec = db.getTime() - da.getTime();
    return diffMSec;
}

// to convert Milliseconds into DD HH:MM:SS format.
public String getDateFromMsec(long diffMSec) {
    int left = 0;
    int ss = 0;
    int mm = 0;
    int hh = 0;
    int dd = 0;
    left = (int) (diffMSec / 1000);
    ss = left % 60;
    left = (int) left / 60;
    if (left > 0) {
        mm = left % 60;
        left = (int) left / 60;
        if (left > 0) {
            hh = left % 24;
            left = (int) left / 24;
            if (left > 0) {
                dd = left;
            }
        }
    }
    String diff = Integer.toString(dd) + " " + Integer.toString(hh) + ":"
            + Integer.toString(mm) + ":" + Integer.toString(ss);
    return diff;

}
}

Answer 2

I know this is an old question, but I ended up doing something slightly different from the accepted answer. People talk about the TimeUnit class, but there were no answers using this in the way OP wanted it.

So here's another solution, should someone come by missing it ;-)

public class DateTesting {
    public static void main(String[] args) {
        String dateStart = "11/03/14 09:29:58";
        String dateStop = "11/03/14 09:33:43";

        // Custom date format
        SimpleDateFormat format = new SimpleDateFormat("yy/MM/dd HH:mm:ss");  

        Date d1 = null;
        Date d2 = null;
        try {
            d1 = format.parse(dateStart);
            d2 = format.parse(dateStop);
        } catch (ParseException e) {
            e.printStackTrace();
        }    

        // Get msec from each, and subtract.
        long diff = d2.getTime() - d1.getTime();

        long days = TimeUnit.MILLISECONDS.toDays(diff);
        long remainingHoursInMillis = diff - TimeUnit.DAYS.toMillis(days);
        long hours = TimeUnit.MILLISECONDS.toHours(remainingHoursInMillis);
        long remainingMinutesInMillis = remainingHoursInMillis - TimeUnit.HOURS.toMillis(hours);
        long minutes = TimeUnit.MILLISECONDS.toMinutes(remainingMinutesInMillis);
        long remainingSecondsInMillis = remainingMinutesInMillis - TimeUnit.MINUTES.toMillis(minutes);
        long seconds = TimeUnit.MILLISECONDS.toSeconds(remainingSecondsInMillis);

        System.out.println("Days: " + days + ", hours: " + hours + ", minutes: " + minutes + ", seconds: " + seconds);
    }
}

Although just calculating the difference yourself can be done, it's not very meaningful to do it like that and I think TimeUnit is a highly overlooked class.

Answer 3

// d1, d2 are dates
long diff = d2.getTime() - d1.getTime();

long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);

System.out.print(diffDays + " days, ");
System.out.print(diffHours + " hours, ");
System.out.print(diffMinutes + " minutes, ");
System.out.print(diffSeconds + " seconds.");

Answer 4

difference-between-two-dates-in-java

Extracted the code from the link

public class TimeDiff {
    /**
     * (For testing purposes)
     *
     */
    public static void main(String[] args) {
        Date d1 = new Date();
        try { Thread.sleep(750); } catch(InterruptedException e) { /* ignore */ }      
        Date d0 = new Date(System.currentTimeMillis() - (1000*60*60*24*3)); // About 3 days ago
        long[] diff = TimeDiff.getTimeDifference(d0, d1);

        System.out.printf("Time difference is %d day(s), %d hour(s), %d minute(s), %d second(s) and %d millisecond(s)\n",
                diff[0], diff[1], diff[2], diff[3], diff[4]);
        System.out.printf("Just the number of days = %d\n",
                TimeDiff.getTimeDifference(d0, d1, TimeDiff.TimeField.DAY));
    }

    /**
     * Calculate the absolute difference between two Date without
     * regard for time offsets
     *
     * @param d1 Date one
     * @param d2 Date two
     * @param field The field we're interested in out of
     * day, hour, minute, second, millisecond
     *
     * @return The value of the required field
     */
    public static long getTimeDifference(Date d1, Date d2, TimeField field) {
        return TimeDiff.getTimeDifference(d1, d2)[field.ordinal()];
    }

    /**
     * Calculate the absolute difference between two Date without
     * regard for time offsets
     *
     * @param d1 Date one
     * @param d2 Date two
     * @return The fields day, hour, minute, second and millisecond
     */
    public static long[] getTimeDifference(Date d1, Date d2) {
        long[] result = new long[5];
        Calendar cal = Calendar.getInstance();
        cal.setTimeZone(TimeZone.getTimeZone("UTC"));
        cal.setTime(d1);

        long t1 = cal.getTimeInMillis();
        cal.setTime(d2);

        long diff = Math.abs(cal.getTimeInMillis() - t1);
        final int ONE_DAY = 1000 * 60 * 60 * 24;
        final int ONE_HOUR = ONE_DAY / 24;
        final int ONE_MINUTE = ONE_HOUR / 60;
        final int ONE_SECOND = ONE_MINUTE / 60;

        long d = diff / ONE_DAY;
        diff %= ONE_DAY;

        long h = diff / ONE_HOUR;
        diff %= ONE_HOUR;

        long m = diff / ONE_MINUTE;
        diff %= ONE_MINUTE;

        long s = diff / ONE_SECOND;
        long ms = diff % ONE_SECOND;
        result[0] = d;
        result[1] = h;
        result[2] = m;
        result[3] = s;
        result[4] = ms;

        return result;
    }

    public static void printDiffs(long[] diffs) {
        System.out.printf("Days:         %3d\n", diffs[0]);
        System.out.printf("Hours:        %3d\n", diffs[1]);
        System.out.printf("Minutes:      %3d\n", diffs[2]);
        System.out.printf("Seconds:      %3d\n", diffs[3]);
        System.out.printf("Milliseconds: %3d\n", diffs[4]);
    }

    public static enum TimeField {DAY,
        HOUR,
        MINUTE,
        SECOND,
        MILLISECOND;
    }
}

Answer 5

If you are able to use external libraries I would recommend you to use Joda-Time, noting that:

Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310).

Example for between calculation:

Seconds.between(startDate, endDate);
Days.between(startDate, endDate);

Answer 6

Create a Date object using the diffence between your times as a constructor,
then use Calendar methods to get values ..

Date diff = new Date(d2.getTime() - d1.getTime());

Calendar calendar = Calendar.getInstance();
calendar.setTime(diff);
int hours = calendar.get(Calendar.HOUR_OF_DAY);
int minutes = calendar.get(Calendar.MINUTE);
int seconds = calendar.get(Calendar.SECOND);