[sqlite] Calculating Average Time

[Jonathan O]

I have searched (archives/google) and haven't found a solution for what I
need and can't think of a solution so below is my question.
I have:
   Job 1 run 1 with a time of '01:00:15'
   Job 1 run 2 with a time of '01:00:21'

What I do is:

select sum(strftime('%H%M%S', time_column))/2 from table;
10018

But I don't know how to get it back into a time format. Is there an easier
way?

Jonathan