Question

I need to calculate the time elapsed from one specific date till now and display it with the same format as StackOverflow questions, i.e.:

15s ago
2min ago
2hours ago
2days ago
25th Dec 08

Do you know how to achieve it with the Java Joda-Time library? Is there a helper method out there that already implements it, or should I write the algorithm myself?

Answer 1

To calculate the elapsed time with JodaTime, use Period. To format the elapsed time in the desired human representation, use PeriodFormatter which you can build by PeriodFormatterBuilder.

Here’s a kickoff example:

DateTime myBirthDate = new DateTime(1978, 3, 26, 12, 35, 0, 0);
DateTime now = new DateTime();
Period period = new Period(myBirthDate, now);

PeriodFormatter formatter = new PeriodFormatterBuilder()
    .appendSeconds().appendSuffix(" seconds ago\n")
    .appendMinutes().appendSuffix(" minutes ago\n")
    .appendHours().appendSuffix(" hours ago\n")
    .appendDays().appendSuffix(" days ago\n")
    .appendWeeks().appendSuffix(" weeks ago\n")
    .appendMonths().appendSuffix(" months ago\n")
    .appendYears().appendSuffix(" years ago\n")
    .printZeroNever()
    .toFormatter();

String elapsed = formatter.print(period);
System.out.println(elapsed);

This prints by now

3 seconds ago
51 minutes ago
7 hours ago
6 days ago
10 months ago
31 years ago

^{_{(Cough, old, cough)}} You see that I’ve taken months and years into account as well and configured it to omit the values when those are zero.