Попробуйте Вы можете найти свой ответ
Date d1 = new GregorianCalendar(2012, 00, 16, 21, 59).getTime();
Date d2 = new GregorianCalendar(2012, 00, 01, 15, 59).getTime();
long diff = d2.getTime() - d1.getTime();
(diff / (1000 * 60 * 60 * 24)); //for counting days
(diff / (1000 * 60 * 60)); //for counting hours
..................... ................... и так далее