Date Difference

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:

package com.test.day10.date;

import java.util.Calendar;

import org.junit.Test;

/**
 * @author BigBird
 * @date 2011-12-11 下午05:19:03
 * @action 测试时间差
 */
public class TimeDifferenceTest {

	@Test
	public void test1() {
		Calendar calendar1 = Calendar.getInstance();
		Calendar calendar2 = Calendar.getInstance();
		calendar1.set(2011, 12, 10, 9, 00, 00);
		calendar2.set(2011, 12, 11, 17, 51, 11);
		long millisecond1 = calendar1.getTimeInMillis();
		long millisecond2 = calendar2.getTimeInMillis();
		long diff = millisecond2 - millisecond1;
		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.");
	}
}

The output of the program is given below:

The Date Different Example
Time in milliseconds: 118271000 milliseconds.
Time in seconds: 118271 seconds.
Time in minutes: 1971 minutes.
Time in hours: 32 hours.
Time in days: 1 days.