asp.net 抓取本月第一天&本月最後一天日期

百度知識家找到的 很實用 筆記起來..

// 本月的第一天           
DateTime firstDate = new DateTime(DateTime.Today.Year, DateTime.Today.Month, 1);
//本月的最后一天
DateTime lastDate = firstDate.AddMonths(1).AddDays(-1);
 
int weekDay = (short)DateTime.Today.DayOfWeek;
 
//本周一的日期
DateTime monday = DateTime.Today.AddDays(1 - weekDay);
//本周六的日期
DateTime saturday = DateTime.Today.AddDays(6 - weekDay);