Using java.util.Date to Find the Difference in Days

gistfile1.txt

public void givenTwoDatesBeforeJava8_whenDifferentiating_thenWeGetSix()
  throws ParseException {
 
    SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy", Locale.ENGLISH);
    Date firstDate = sdf.parse("06/24/2017");
    Date secondDate = sdf.parse("06/30/2017");

    long diffInMillies = Math.abs(secondDate.getTime() - firstDate.getTime());
    long diff = TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);

    assertEquals(6, diff);
}