Someone

ELSE IF @SetName = 'DY'
	SELECT  DATEPART([year], TestDateTime) AS Year, DATEPART(DY, TestDateTime) AS DayOfYear, COUNT(TestDateTime) AS NumberOfOutages, 
		SUM(DATEDIFF([minute], TestDateTime, next_test)) AS DownTimeInMinutes
			FROM (SELECT     e.TestID, e.ResultID, e.TestDateTime,
			(SELECT     MIN(d .TestDateTime)
        			FROM          Result d
	WHERE      (d .TestID =@TestID AND d.TestDateTime >= e.TestDateTime AND datepart(DY, d.TestDateTime) =datepart(DY, e.TestDateTime) AND d .TestSimpleStatus <> e.TestSimpleStatus)) AS next_test
	FROM          Result e
	WHERE      (e.TestID = @TestID) AND (e.TestSimpleStatus = 'DOWN') AND (TestDatetime >= '1/1/2005')) x
	WHERE     (DATEDIFF([minute], TestDateTime, next_test) > 0)
	GROUP BY  DATEPART(DY, TestDateTime), DATEPART([year], TestDateTime)
	ORDER BY DATEPART(DY, TestDateTime) DESC, DATEPART([year], TestDateTime) DESC