How to calculate time difference in java?

Question

I want to subtract two timeperiods say 16:00:00 from 19:00:00. Is there any java function for this? The results can be in milliseconds, seconds, or minutes.

Answer 1

String time1 = "16:00:00";
String time2 = "19:00:00";

SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
Date date1 = format.parse(time1);
Date date2 = format.parse(time2);
long difference = date2.getTime() - date1.getTime(); 

Difference is in milliseconds.

I modified sfaizs post.

Answer 2

TO get pretty timing differences, then

// 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 3

Аlternative option if time from different days is taken, for example: 22:00 and 01:55.

public static long getDiffTime(Date date1, Date date2){
        if (date2.getTime() - date1.getTime() < 0) {// if for example date1 = 22:00, date2 = 01:55.
            Calendar c = Calendar.getInstance();
            c.setTime(date2);
            c.add(Calendar.DATE, 1);
            date2 = c.getTime();
        } //else for example date1 = 01:55, date2 = 03:55.
        long ms = date2.getTime() - date1.getTime();

        //235 minutes ~ 4 hours for (22:00 -- 01:55).
        //120 minutes ~ 2 hours for (01:55 -- 03:55).
        return TimeUnit.MINUTES.convert(ms, TimeUnit.MILLISECONDS);
    }

Answer 4

import java.util.Date;
...
Date d1 = new Date();
...
...
Date d2 = new Date();
System.out.println(d2.getTime()-d1.getTime()); //gives the time difference in milliseconds. 
System.out.println((d2.getTime()-d1.getTime())/1000); //gives the time difference in seconds.

and, to show in a nicer format, you can use:

    DecimalFormat myDecimalFormatter = new DecimalFormat("###,###.###");
    System.out.println(myDecimalFormatter.format(((double)d2.getTime()-d1.getTime())/1000));

Answer 5

Just like any other language; convert your time periods to a unix timestamp (ie, seconds since the Unix epoch) and then simply subtract. Then, the resulting seconds should be used as a new unix timestamp and read formatted in whatever format you want.

Ah, give the above poster (genesiss) his due credit, code's always handy ;) Though, you now have an explanation as well :)

Answer 6

Java 8

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

LocalDateTime dateTime1= LocalDateTime.parse("2014-11-25 19:00:00", formatter);
LocalDateTime dateTime2= LocalDateTime.parse("2014-11-25 16:00:00", formatter);

long diffInMilli = java.time.Duration.between(dateTime1, dateTime2).toMillis();
long diffInSeconds = java.time.Duration.between(dateTime1, dateTime2).getSeconds();
long diffInMinutes = java.time.Duration.between(dateTime1, dateTime2).toMinutes();