Substract seconds from current time using Calendar add method in Java

/*  w  w w .  jav a 2  s .  co  m*/
import java.util.Calendar;

public class Main {

  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    System.out.println("Current time : " + now.get(Calendar.HOUR_OF_DAY) + ":"
        + now.get(Calendar.MINUTE) + ":" + now.get(Calendar.SECOND));

    now = Calendar.getInstance();
    now.add(Calendar.SECOND, -50);
    System.out.println("Time before 50 minutes : " + now.get(Calendar.HOUR_OF_DAY) + ":"
        + now.get(Calendar.MINUTE) + ":" + now.get(Calendar.SECOND));  }
}