Date Difference Java

This example learns how to make the difference between two dates and how to convert milliseconds into seconds, seconds into minutes, minutes into hours, hours into days.

Here we are using Calendar, an abstract base class that extends Object class and makes a difference between a Date object and a set of integer fields. Calendar class provides a getInstance()  method for returning a Calendar object whose time fields have been initialized with the current date and time.

The methods used:
setTimeInMillis(long millis): This method is used to set current time in calendar object.

getInstance(): This method is used to get a calendar using the default time zone, locale and current time.

The code of the program is given below:

import java.util.Calendar;

import java.util.Date;

public class DateDifferent {

    public static void main(String[] args) {

        Date date1 = new Date(2009, 01, 10);

        Date date2 = new Date(2009, 07, 01);

        Calendar calendar1 = Calendar.getInstance();

        Calendar calendar2 = Calendar.getInstance();

        calendar1.setTime(date1);

        calendar2.setTime(date2);

        long milliseconds1 = calendar1.getTimeInMillis();

        long milliseconds2 = calendar2.getTimeInMillis();

        long diff = milliseconds2 - milliseconds1;

        long diffSeconds = diff / 1000;

        long diffMinutes = diff / (60 * 1000);

        long diffHours = diff / (60 * 60 * 1000);

        long diffDays = diff / (24 * 60 * 60 * 1000);

        System.out.println("\nThe Date Different Example");

        System.out.println("Time in milliseconds: " + diff + " milliseconds.");

        System.out.println("Time in seconds: " + diffSeconds + " seconds.");

        System.out.println("Time in minutes: " + diffMinutes + " minutes.");

        System.out.println("Time in hours: " + diffHours + " hours.");

        System.out.println("Time in days: " + diffDays + " days.");

    }

}