LibreOffice Calc: How to get total for HH:MM:SS cells

Question

I'd like to take a group of cells in the HH:MM:SS format, and add them up. I don't want to have the value wrap on the 24 hour clock. I just want an absolute total of the values. (The sum function seems to wrap by default).

So if I have:

20:00:00
20:00:00
00:10:00
00:00:10
00:00:10

I want to end up with:

40:10:20

A contrived example, but it gets across what I'm looking for.

Answer 1

It's a matter of formatting the cells. You will have to apply the format code [HH]:MM:SS. It's already predefined:

(Screenshot from LibreOffice 3.4.3)