Difference between two dates SQL Server

Question

I'm searching a way to get the difference between two times in SQL Server.

I would like a format hh:mm:ss

Example : 23:00:00 - 18:09:00 = 04:51:00

I tried with datediff() but it only returns hours, minutes or seconds

[EDIT] :

For example : 23:00:00 + 02:00:00 = 01:00:00, how to get 25:00:00?

Answer 1

You can convert to a time:

select dateadd(second, datediff(second, date1, date2), cast('0:00:00' as time))

You can then use format() or convert() to format the value as a string the way you want.

Answer 2

Example

Declare @T1 time = '23:00'
Declare @T2 time = '18:09'

Select cast(cast(@T1 as datetime) - cast(@T2 as datetime) as time)

Returns

04:51:00.0000000

Or you can use Format() if 2012+

Select format(cast(@T1 as datetime) - cast(@T2 as datetime),'HH:mm:ss')

Returns

04:51:00

Answer 3

Though Others have already answered correctly. I would like to add another version.

declare @StartTime datetime, @EndTime datetime

select @StartTime = '08:40:18',@EndTime='18:52:48'

select  convert(varchar(5),DateDiff(s, @StartTime, @EndTime)/3600)+':'
    +   convert(varchar(5),DateDiff(s, @StartTime, @EndTime)%3600/60)+':'
    +   convert(varchar(5),(DateDiff(s, @StartTime, @EndTime)%60)) as [hh:mm:ss]

Output: 10:12:30