java8 두 날짜 차이값 구하기 (LocalDateTime, ChronoUnit)

Date endDate = new Date();
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -10);
Date startDate = new Date(cal.getTimeInMillis());

LocalDateTime start = LocalDateTime.ofInstant(startDate.toInstant(), ZoneId.systemDefault());
LocalDateTime end = LocalDateTime.ofInstant(endDate.toInstant(), ZoneId.systemDefault());

long days = ChronoUnit.DAYS.between(start, end);​