CREATE TABLE #Calendar (Dt DATETIME);

DECLARE @startDate DATETIME, @endDate DATETIME;
SET @startDate = '20110101';
SET @endDate = '20110131';

;WITH cte AS
(
	SELECT @startDate AS Dt
	UNION ALL
	SELECT DATEADD(dd,1,dt) FROM cte 
	WHERE dt < @endDate
)
INSERT INTO #Calendar SELECT Dt FROM cte;

;WITH e AS 
(
	SELECT DISTINCT EmpNo FROM YourTable
)
SELECT
	e.EmpNo,
	c.Dt
FROM
	e
	CROSS JOIN #Calendar c
	LEFT JOIN YourTable y ON y.EmpNo = e.EmpNo AND y.Dt = c.Dt
WHERE
	y.Dt IS NULL;