说明：  极其完整的nextday程序 虽然功能简单 输入一天 输出下一天 但是程序容错能力极强 因为是软件测试的作业 可以说通过了各种测试条件的好代码
(very integrity of the nextday procedures Although the functional day simple input output next day but can fault tolerant procedures Force is strong because the software testing operations can be said through the various tests for the good code)