Date date1 = new Date(0); // 01.01.1970 00:00 Uhr
Date date2 = new Date(0); // 01.01.1970 00:00 Uhr
Date date3 = new Date();  // Heute

System.out.println(date1);
System.out.println(date2);

System.out.println("--- Compare Dates ---");
// Ausgabe einer Reihe von Vergleichen
System.out.println(date1.equals(date2));
System.out.println(date1.equals(date3));
System.out.println(date1.before(date2));
System.out.println(date1.before(date3));
System.out.println(date1.after(date2));
System.out.println(date1.after(date3));
System.out.println(date1.compareTo(date2));
System.out.println(date1.compareTo(date3));

Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
Calendar cal3 = Calendar.getInstance();

cal1.setTime(new Date(0)); // 01.01.1970 00:00 Uhr
cal2.setTime(new Date(0)); // 01.01.1970 00:00 Uhr

System.out.println("--- Compare Calender ---");

// Ausgabe einer Reihe von Vergleichen
System.out.println(cal1.equals(cal2));
System.out.println(cal1.equals(cal3));
System.out.println(cal1.before(cal2));
System.out.println(cal1.before(cal3));
System.out.println(cal1.after(cal2));
System.out.println(cal1.after(cal3));