java取日期之间的日数

private int daysBetween(Date now, Date returnDate) { Calendar cNow = Calendar.getInstance(); Calendar cReturnDate = Calendar.getInstance(); cNow.setTime(now); cReturnDate.setTime(returnDate); setTimeToMidnight(cNow); setTimeToMidnight(cReturnDate); long todayMs = cNow.getTimeInMillis(); long returnMs = cReturnDate.getTimeInMillis(); long intervalMs = todayMs - returnMs; return millisecondsToDays(intervalMs); } private int millisecondsToDays(long intervalMs) { return (int) (intervalMs / (1000 * 86400)); } private void setTimeToMidnight(Calendar calendar) { calendar.set(Calendar.HOUR_OF_DAY, 0); calendar.set(Calendar.MINUTE, 0); calendar.set(Calendar.SECOND, 0); }