算日期差的小东西

新版jdk自带。。。。

LocalDate startTime = LocalDate.of(1990, 1, 1);

LocalDate endTime = LocalDate.of(2018, 6, 6);

LocalDate nowTime = LocalDate.now();

System.out.println("与现在时间的相差天数："+（nowTime.toEpochDay() - startTime.toEpochDay()）);

System.out.println("与2018-06-06相差天数："+（endTime.toEpochDay() - startTime.toEpochDay()）);