Add another 12 hours and print out the date and time in Java

//from   w w  w.ja  va  2s  .  c o  m
import java.text.DateFormat;
import java.util.Calendar;

public class Main {
  public static void main(String s[]) {
    Calendar cal = Calendar.getInstance();
    DateFormat df = DateFormat.getDateTimeInstance(DateFormat.FULL,
        DateFormat.MEDIUM);

    System.out.println(df.format(cal.getTime()));

    cal.add(Calendar.AM_PM, 1);
    System.out.println(df.format(cal.getTime()));
  }
}