If you are looking for the Monday that starts a work week and/or the Friday that ends the work week, this is how you do it in SQL:
DECLARE @Today AS DATETIME SET @Today = GETDATE() SELECT DATEADD(wk, DATEDIFF(wk, 0, @Today), 0) AS Monday, DATEADD(wk, DATEDIFF(wk, 4, @Today), 4) AS Friday