用可视化的界面，实现一个多功能万年历。该程序可以具有常用的计算闰年与平年、某一天是周几、公历与阴历转换等功能，实用性很强。-With a visual interface to achieve a versatile calendar. The program can be used calculate the leap year and the average, one day of the week, the Gregorian calendar and the lunar calendar