该日期类①能够输入、输出日期信息，并能够对他们进行处理。

②能够计算你所要计算的日期的这一天的前一天、后一天的日期以及该显示日期是否是闰年。

③能够计算您所要计算的这一天的前面d（d为任意整数）天的日期；

能够计算您所要计算的这一天的后d（d为任意整数）天的日期。

程序兼顾到了各个方面:包括出错处理，闰年的特殊情况，以及年初第一天,月初第一天，月末最后一天，年末最后一天的进位退位。

-① category that date to the import, export date information, and be able to deal with them. ② you are able to calculate the date to calculate the day before this day, one day after the date of the show is a leap year date. ③ you can calculate to calculate the day in front of the d (d is arbitrary integer) days of the date　able to calculate that you have to calculate the day after the d (d is arbitrary integer) days of the date. Procedures to take into account various aspects: including error handling, the special circumstances of a leap year, as well as the beginning of the first day of the beginning of the first day, at the end of the last day of the end of the last day of the binary step down.