Find date after / before in java

private static final long MILLISECONDS_IN_SECOND = 1000;
private static final long SECONDS_IN_MINUTE = 60;
private static final long MINUTES_IN_HOUR = 60;
private static final long HOURS_IN_DAY = 24;
private static final long MILLISECONDS_IN_DAY = MILLISECONDS_IN_SECOND *
        SECONDS_IN_MINUTE *
        MINUTES_IN_HOUR *
        HOURS_IN_DAY;
public Date addDays (Date date, int days)
{
 return new Date (date.getTime () + (days * MILLISECONDS_IN_DAY));
}

Date calculation

This sample code is used for Date calculation in Java.

Format :  objectCalendar.add(type, numeric);

type :  Calendar.MONTH, Calendar.YEAR, Calendar.DAY, Calendar.WEEK.

Example code :

import java.util.Calendar;

public class CalendarAddExample {
    public static void main(String[] args) {
        Calendar cal = Calendar.getInstance();

        System.out.println("Today : " + cal.getTime());

        // Subtract 30 days from the calendar
        cal.add(Calendar.DATE, -30);
        System.out.println("30 days ago: " + cal.getTime());

        // Add 10 months to the calendar
        cal.add(Calendar.MONTH, 10);
        System.out.println("10 months later: " + cal.getTime());

        // Subtract 1 year from the calendar
        cal.add(Calendar.YEAR, -1)
        System.out.println("1 year ago: " + cal.getTime());
    }
}