How to calculate if two dates are more than one year appart in Java.

Recently I had to do dates validation. I was passing two dates and I had to make sure that the difference between these dates was not more than one year.

I set up a small Java project using Joda Time library.

Here's my code:

import org.joda.time.DateTime;

import org.joda.time.Months;

import org.joda.time.format.DateTimeFormat;

import org.joda.time.format.DateTimeFormatter;

public class TimeCheck {

    public static void main(String[] args) {

       // half-a-year difference:

       calcTime("20100101", "20100601");

       // nine-months difference:

       calcTime("20100101", "20100901");

      // more-than-a-year difference:

      calcTime("20100101", "20110901");

    }

   

    private static void calcTime (String fromDate, String toDate) {

        DateTimeFormatter dateDecoder = DateTimeFormat.forPattern("yyyyMMdd");

        DateTime startDate = dateDecoder.parseDateTime(fromDate);

        System.out.println("start time: " + startDate.toString());

        DateTime endDate = dateDecoder.parseDateTime(toDate);

        System.out.println("start time: " + endDate.toString());

        Months diff = Months.monthsBetween(startDate, endDate);

        System.out.println("diff is: " + diff.getMonths());

        boolean moreThanYear = diff.isGreaterThan(Months.TWELVE);

        if (moreThanYear) {

            System.out.println("result is: " + moreThanYear);

        }

        // not needed here but I show how to add one year to target date:

        DateTime newEnd = endDate.plusYears(1);

        System.out.println("new end:    " + newEnd.toString()); 

    }

}