import java.util.Calendar;
 
public class HourstoCurrDate {
 
  public static void main(String[] args) {
   
    //create Calendar instance
    Calendar now = Calendar.getInstance();
 
    System.out.println("Current Date : " + (now.get(Calendar.MONTH) + 1)
                        + "-"
                        + now.get(Calendar.DATE)
                        + "-"
                        + now.get(Calendar.YEAR));
   
    System.out.println("Current time : " + now.get(Calendar.HOUR_OF_DAY)
                      + ":"
                      + now.get(Calendar.MINUTE)
                      + ":"
                      + now.get(Calendar.SECOND));
                     
    //add hours to current date using Calendar.add method
    now.add(Calendar.HOUR,10);
 
    System.out.println("New time after adding 10 hours : "
                      + now.get(Calendar.HOUR_OF_DAY)
                      + ":"
                      + now.get(Calendar.MINUTE)
                      + ":"
                      + now.get(Calendar.SECOND));
 
    /*
     * Java Calendar class automatically adjust the date accordingly if adding
     * hours to the current time causes current date to be changed.
     */
     
    System.out.println("New date after adding 10 hours : "
                        + (now.get(Calendar.MONTH) + 1)
                        + "-"
                        + now.get(Calendar.DATE)
                        + "-"
                        + now.get(Calendar.YEAR));
   
    //substract hours from current date using Calendar.add method
    now = Calendar.getInstance();
    now.add(Calendar.HOUR, -3);
 
    System.out.println("Time before 3 hours : " + now.get(Calendar.HOUR_OF_DAY)
                      + ":"
                      + now.get(Calendar.MINUTE)
                      + ":"
                      + now.get(Calendar.SECOND));
   
  }
}