declare @Date1 datetime ='10/3/2012 12:02:16 PM'
declare @Date2 datetime = '9/21/2012 11:01:32 PM'
SELECT STUFF( CONVERT(varchar(8),timediff,108),1,CHARINDEX(':',CONVERT(varchar(8),timediff,108))-1,DATEDIFF(dd,0,timediff) * 24 + DATEPART(hh,timediff))
FROM
(
SELECT DATEADD(ss,ABS(DATEDIFF(ss,@Date1,@Date2)),0) AS timediff
)t
------------------------------------------------------------------------------------------------------
SQL Server MVP
http://visakhm.blogspot.com/