Add Days

import java.util.*;

public class AddDaysToDate {
    public static void main(String[] args) {
        Date date=new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);

        System.out.println("Today : " + cal.getTime());
        cal.add(Calendar.DATE, 2);
        System.out.println("After 2 days: " + cal.getTime());
    }
}

Subtract Days

import java.util.*;

public class SubtractDaysToDate {
    public static void main(String[] args) {
        Date date=new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);

        System.out.println("Today : " + cal.getTime());
        cal.add(Calendar.DATE, -2);
        System.out.println("Before 2 days: " + cal.getTime());
    }
}