Roll through hours & months in a java

Roll through hours & months

import java.util.*;

             public class Main

{

   public static void main(String[] args) throws Exception

{

      Date d1 = new Date();

      Calendar cl = Calendar. getInstance();

      cl.setTime(d1);

      System.out.println("today is "+ d1.toString());

      cl. roll(Calendar.MONTH, 100);

System.out.println("date after a month will be " + cl.getTime().toString() );

      cl. roll(Calendar.HOUR, 70);

      System.out.println("date after 7 hrs will be "+ cl.getTime().toString() );

   }

}