实现对时间的不同格式的输出，计算当前时间或者之后之前n天时间是多少，判断当前是否是闰年。函数已经写好，根据自己的需要进行输出即可。-Achieve different formats of output versus time to calculate the current time, or after n days before the number, it is judged whether the current is a leap year. Function has been wri