C# 获取月份有多少天/获取某天是星期几

获取某年某月一共有多少天

int daysCount = DateTime.DaysInMonth(2019,12);

获取某天是周几

 string[] Days = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" }; 
 void Start()
 {
     string week = Days[Convert.ToInt32(DateTime.Parse($"2019/12/1").DayOfWeek.ToString("d"))]; 
 }

借鉴文章

对应星期

https://blog.csdn.net/zhu1991_/article/details/74725894

月份天数

https://blog.csdn.net/weixin_42213195/article/details/101103597