Java Program To Add or substract hours to current time using Java Calendar

/*
  Add or substract hours to current time using Java Calendar
  This example shows how to add or substract hours in current time
  using Java Calendar class.
*/

import java.util.Calendar;

public class AddHoursToCurrentDate {

  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));
 
  }
}

/*
Typical output would be
Current Date : 12-25-2007
Current time : 18:31:42
New time after adding 10 hours : 4:31:42
New date after adding 10 hours : 12-26-2007
Time before 3 hours : 15:31:42
*/