Difference in time using Java - going from before midnight to after midnight

Question

I'm working on a program that will return the difference in time (how many hours, mins) that has elapsed between two points in time. I need to be able to calculate the time, also, if the times are, say, 11:00 pm to 3:00 am. How would I go about doing this, as well as calculating the time from say 8:00 am to 5:00 pm?

Thanks!

This is not going to be even a little bit simple in real life. Use [JODA Time](http://joda-time.sourceforge.net/). (Avoid the JDK calendar libraries if you can; JODA is much better designed.) — Louis Wasserman, Apr 27 '12 at 19:00
@LouisWasserman Exactly. People voting this down aren't really thinking things through. — erickson, Apr 27 '12 at 19:02
@erickson: I don't think people voting it down are doing so because it's simple - I suspect they're doing so because the OP hasn't shown *any* indication of having tried to do it themselves. — Jon Skeet, Apr 27 '12 at 19:06
possible duplicate: [Calculate date/time difference in java](http://stackoverflow.com/q/5351483/1048330) — tenorsax, Apr 27 '12 at 19:16

score 1 · Answer 1 · edited Feb 01 '19 at 15:07

1

public static void main(String[] av) {
    /** The date at the end of the last century */
    Date d1 = new GregorianCalendar(2000, 11, 31, 23, 59).getTime();

    /** Today's date */
    Date today = new Date();

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

    System.out.println("The 21st century (up to " + today + ") is "
        + (diff / (1000 * 60 * 60 * 24)) + " days old.");
}

edited Feb 01 '19 at 15:07

tawheed

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answered Apr 27 '12 at 19:00

CAA

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The 21st century's age varies with timezone :) – Marko Topolnik Apr 27 '12 at 19:15
timezones are a science for themselves.... in my eyes the op just asked for howto devide 2 dates... i just hope this does the job for him^^# – CAA Apr 28 '12 at 07:25

score 1 · Answer 2 · answered Dec 10 '18 at 19:09

If someone is looking for a solution, you can do like this answer

String time = "22:00-01:05";
String[] parts = time.split("-");

LocalTime start = LocalTime.parse(parts[0]);
LocalTime end = LocalTime.parse(parts[1]);
if (start.isBefore(end)) { // normal case
    System.out.println(Duration.between(start, end));
} else { // 24 - duration between end and start, note how end and start switched places
    System.out.println(Duration.ofHours(24).minus(Duration.between(end, start)));
}

Difference in time using Java - going from before midnight to after midnight

2 Answers2