select
EventID,
TotalSeconds / 3600 as Hours,
(TotalSeconds % 3600) / 60 as Minutes,
TotalSeconds % 60 as Seconds
from
(
select EventID, DateDiff(second, StartDate, EndDate) as TotalSeconds
from Events
) x
EventID Hours Minutes Seconds
----------- ----------- ----------- -----------
1 6 11 22
2 7 42 29
3 0 21 6
4 3 51 21
5 1 15 53
6 5 24 0
7 16 50 2
(7 row(s) affected)