Calendar

代码说明：

说明：  本程序主要是一个时钟软件，包括一个时钟表和一个日历。程序自动运行时，显示系统当前日期和时间，日期和时间可以由用户自行更改。内含一个详细说明文档。 (This program is primarily a clock software, including a time clock and a calendar. The program automatically runs, display the current system date and time, date and time can be changed by the user. Contains a detailed description of the document.)