编程思路：按照以上背景知识可得判断闰年的规律：某年年份如果能被4整除但不能被100整除，或者能被400整除则是闰年。由此规则可推得计算万年历的公式：

s=X-1+[X-1]/4-[X-1]/100+[x-1]/400+c 上式中：X为公元年数（如2003年）；C 为从元旦起，到要算的那天总数（如2003年3月23日，C=31＋28＋23＝82）。S/7余数是星期几。

-Programming idea: In accordance with the above background knowledge available to determine the law of a leap year: a year to be 4 years if divisible by 100 but not divisible, or can be divisible by 400 is a leap year. This rule may push calendar calculation formula: s = X-1+ [X-1]/4- [X-1]/100+ [x-1]/400+ c the type in: X number of years for the Year [such as in 2003]　C starting from New Year' s Day to the day to count the total number of [such as March 23, 2003, C = 31+28+23 = 82]. S/7 more than the number of the week.