TimeUnit

// 将24小时转化为NANOSECONDS
TimeUnit.NANOSECONDS.convert(24, TimeUnit.HOURS)


Runnable registerMenuToBrm = new Runnable() {
    @Override
    public void run() {
        TimeUnit.SECONDS.sleep(2L);
    }
};

// 将1天转化为24小时
TimeUnit.DAYS.toHours( 1 )

// 把3天转化成小时
TimeUnit.HOURS.convert( 3 , TimeUnit.DAYS )