Dear Dinesh,
Hope this will help you.
select DATEDIFF(day,col1,col2) AS NumberOfDays,
DATEDIFF(hour,col1,col2) AS NumberOfHours,
DATEDIFF(minute,col1,col2) AS NumberOfMinutes FROM Your_Table
select DATEDIFF(day,2012-06-19,2012-06-20) AS NumberOfDays,
DATEDIFF(hour,2012-06-19,2012-06-20) AS NumberOfHours,
DATEDIFF(minute,2012-06-19,2012-06-20) AS NumberOfMinutes FROM Your_Table
Regards,
AP