DECLARE @CurrDay DATETIME=GETDATE()

--SET @CurrDay=CAST(('2013-01-10')AS DATETIME)

--SET @CurrDay=CAST(('2012-01-10')AS DATETIME)

DECLARE @CurrWK INT=DATEPART(wk,@CurrDay)

DECLARE @YearFisrtDay DATETIME=CAST((DATENAME(yy,@CurrDay)+'-01-01') AS DATETIME)

PRINT @YearFisrtDay

--这一年的第一天是星期几

DECLARE @YearFistWK INT=DATEPART(dw,@YearFisrtDay)

PRINT @YearFistWK

--总多少天 -第一天是属于的周

PRINT DATEADD(DAY,(@CurrWK-1)*7-@YearFistWK+1,@YearFisrtDay)