Hey Andras, are u sure that will give what you said. Or you just missed something in between?

Here are the results from it...

SELECTDATEPART( wk, '3/12/2007' ) * 53 + DATEPART( yyyy, '3/12/2007' ),

DATEPART( wk, '3/12/2007' ) * 53, DATEPART( wk, '3/12/2007' ), DATEPART( yyyy, '3/12/2007' )

--Results

2590583112007

Here is what I use in my projects...

DECLARE @sdtAnyDate SMALLDATETIME

SET @sdtAnyDate = '03-Dec-2007'

SELECTDATEADD( DAY, 1 - DATEPART( dw, @sdtAnyDate), @sdtAnyDate ) AS WeekStartDate,

@sdtAnyDate AS InputDate,

DATEADD( DAY, 7 - DATEPART( dw, @sdtAnyDate ), @sdtAnyDate ) AS WeekEndDate