https://blog.csdn.net/gaobosky/article/details/81387773?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522162616030816780366537910%2522%252C%2522scm%2522%253A%252220140713.130102334..%2522%257D&request_id=162616030816780366537910&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~all~sobaiduend~default-3-81387773.first_rank_v2_pc_rank_v29_1&utm_term=c%E8%AF%AD%E8%A8%80%E4%B8%87%E5%B9%B4%E5%8E%86%E7%A8%8B%E5%BA%8F%E4%BB%A3%E7%A0%81&spm=1018.2226.3001.4187这是CSDN上一个万年历，其中格式化输出不理解，需要个详细点的注释，thanks！
按星期每行输出一个星期的日期，格式化输出年月日呢
