Got part of the way there... must have done something silly, because the math looks backwards... I created some sample records to play with... hopefully it's enough.

SELECT EmpID, InOutDate

,MIN(InOutTimeStamp) AS InStamp

,MAX(InOutTimeStamp) AS OutStamp

,DATEDIFF(n,MAX(InOutTimeStamp),MIN(InOutTimeStamp)) AS MinsWorked

FROM

(SELECT EmpID

, InOutDate

, InOutTimeStamp

, ROW_NUMBER() OVER (PARTITION BY EmpID, InOutDate ORDER BY EmpID, InOutDate) AS rn

FROM

(

SELECT EmpID

, InOutTimeStamp

, CAST(InOutTimeStamp AS DATE) AS InOutDate

FROM

(SELECT 1 AS EmpID,'2-1-2014 8:30' AS InOutTimeStamp

UNION ALL

SELECT 1, '2-1-2014 18:30'

UNION ALL

SELECT 1, '2-2-2014 7:30'

UNION ALL

SELECT 1, '2-2-2014 15:30'

UNION ALL

SELECT 2, '2-1-2014 6:30'

UNION ALL

SELECT 2, '2-1-2014 19:30') x

) y

) z

GROUP BY EmpID, InOutDate

ORDER BY EmpID, InOutDate;