C#根据当前时间确定日期范围（本周、本月、本季度、本年度）[转]

c#版本:

DateTime dt = DateTime.Now; //当前时间

DateTime startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d"))); //本周周一

DateTime endWeek = startWeek.AddDays(6); //本周周日

DateTime startMonth = dt.AddDays(1 - dt.Day); //本月月初

DateTime endMonth = startMonth.AddMonths(1).AddDays(-1); //本月月末

//DateTime endMonth = startMonth.AddDays((dt.AddMonths(1) - dt).Days - 1); //本月月末

DateTime startQuarter = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day); //本季度初

DateTime endQuarter = startQuarter.AddMonths(3).AddDays(-1); //本季度末

DateTime startYear = new DateTime(dt.Year, 1, 1); //本年年初

DateTime endYear = new DateTime(dt.Year, 12, 31); //本年年末

SQL版本：

select dateadd(day, 2 - datepart(dw,getdate()), getdate()) [星期一],dateadd(day, 8 - datepart(dw,getdate()), getdate()) [星期日]