C# 和SQL 计算时间:周一,周日,月初,月末,季初,季末...

 public void GetDate(DateTime thisDate, out DateTime endWeek, out DateTime endMonth, out DateTime endQuarter, out DateTime endYear)
        {
            //DateTime dt = Convert.ToDateTime(thisDate.ToString("yyyy-MM-dd"));
            //DateTime startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d")));   //本 周周一 
            //endWeek = startWeek.AddDays(7).AddSeconds(-1);   //本 周周日 
            //DateTime beginMonth = dt.AddDays(1 - dt.Day);    //本月月初
            //endMonth = beginMonth.AddMonths(1).AddSeconds(-1); //本月月末
            //DateTime startQuarter = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day);   //本 季度初 
            //endQuarter = startQuarter.AddMonths(3).AddSeconds(-1);   //本 季度末 
            //DateTime startYear = new DateTime(dt.Year, 1, 1);   //下年 年初 
            //endYear = new DateTime(dt.Year + 1, 1, 1).AddSeconds(-1);    //本年 年末 

            DateTime dt = Convert.ToDateTime(thisDate.ToString("yyyy-MM-dd"));
            DateTime startWeek;
            if (Convert.ToInt32(dt.DayOfWeek.ToString("d")) == 0)
            {
                startWeek = dt.AddDays(-6);
            }
            else
            {
                startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d")));   //本 周周一 
            }
            // DateTime startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d")));   //本 周周一 
            endWeek = startWeek.AddDays(7).AddSeconds(-1);   //本 周周日 
            DateTime beginMonth = dt.AddDays(1 - dt.Day);    //本月月初
            endMonth = beginMonth.AddMonths(1).AddSeconds(-1); //本月月末
            DateTime startQuarter = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day);   //本 季度初 
            endQuarter = startQuarter.AddMonths(3).AddSeconds(-1);   //本 季度末 
            DateTime startYear = new DateTime(dt.Year, 1, 1);   //下年 年初 
            endYear = new DateTime(dt.Year + 1, 1, 1).AddSeconds(-1);    //本年 年末 
        }

1.上面注掉的,如果传入时间是星期天的话,就会把下周一当成本周一.在周的计算上就会有问题.

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2.下面的是在SQL中计算相关的一些时间参数.

DECLARE @MondayTime varchar(10)
	DECLARE @SundayTime varchar(10)
	DEClARE @ThisDate datetime
	DEClARE @EndWeekDate datetime  --周末时间
	Declare @EndMonth datetime     --月末时间
	DECLARE @EndQuarter datetime   --季末时间
	set @ThisDate=dateadd(day,-1,getdate())
	IF(datepart(weekday,@ThisDate)-2 < 0)
	BEGIN
	 SET @MondayTime = convert(varchar(10),dateadd(dd,-1,@ThisDate)-(datepart(weekday,dateadd(dd,-1,@ThisDate))-2),120)
	 SET @SundayTime = convert(varchar(10),dateadd(dd,-1,@ThisDate)+(8-datepart(weekday,dateadd(dd,-1,@ThisDate))),120)
	END
	ELSE
	 BEGIN
	  SET @MondayTime =convert(varchar(10),@ThisDate-(datepart(weekday,@ThisDate)-2),120)
	  SET @SundayTime =convert(varchar(10),@ThisDate+(8-datepart(weekday,@ThisDate)),120)
	 END
	 
	 set @EndWeekDate = convert(datetime,@SundayTime)
	 set @EndWeekDate= dateadd(second,59,dateadd(minute,59,dateadd(hour,23,@EndWeekDate))) 
	 --select @EndWeekDate
	 
	 
	 set @EndMonth=dateadd(second,59,dateadd(minute,59,dateadd(hour,23,dateadd(month,1+datediff(month,0,@ThisDate),0)-1)))
	 --select @EndMonth as endMonth
	 
	 declare @Num int;
	 declare @spanMonth int;
	 set @Num= datepart(MM,@EndMonth)
	 if(@Num<=3)
		set @spanMonth = 3-@Num
	 else if(@Num>3 and @Num<=6)
		set	@spanMonth = 6-@Num
	 else if(@Num>6 and @Num<=9)
   		set @spanMonth = 9-@Num
	 else if(@Num>9 and @Num<=12)
		set	@spanMonth = 12-@Num
	 set @EndQuarter= dateadd(month, @spanMonth,@EndMonth)
	 
	 --select @EndQuarter as endQuarter