// Einen Tag zum heutigen Tag hinzurechnen
Date tomorrow = new Date();
long delta = 1*24*60*60*1000;  // 1 Tag in Millisekunden
tomorrow.setTime(tomorrow.getTime()+delta);
System.out.println("Morgen ist " + tomorrow);

System.out.println("--- Addition von Zeitangaben ---");
// Addieren eines Tages, eines Monats und eines Jahres zum akt. Datum
Calendar cal = Calendar.getInstance();
System.out.println(cal.getTime());
cal.add(Calendar.DAY_OF_MONTH, 1);
System.out.println(cal.getTime());
cal.add(Calendar.MONTH, 1);
System.out.println(cal.getTime());
cal.add(Calendar.YEAR, 1);
System.out.println(cal.getTime());

System.out.println("--- Addition von Monaten ---");

cal.set(Calendar.MONTH, 2);
cal.set(Calendar.DAY_OF_MONTH, 31);
System.out.println(cal.getTime());
cal.roll(Calendar.MONTH, 1);
System.out.println(cal.getTime());
cal.roll(Calendar.MONTH, 1);
System.out.println(cal.getTime());

System.out.println("--- Unterschied add() und roll() ---");
Calendar cal2 = Calendar.getInstance();
System.out.println(cal2.getTime());
cal2.add(Calendar.MONTH, 13);
System.out.println(cal2.getTime());
cal2.roll(Calendar.MONTH, 13);
System.out.println(cal2.getTime());