JE McGimpsey wrote in
:

This works for me:

A1: 0:00:01,234
A2: 0:00:04,567
A3: 0:00:07,890

B1: =SUM(A:A) === 0:00:13,691

when all cells are formatted with

Format/Cells/Number/Custom h:mm:ss,000

No programmer's trick needed.

when all In article ,
Bllich wrote:

I calculated a1+a2 on my own, or how should I say "on paper"...
the problem is in Excel .. i can't do a3=a1+a2 because i have those
,xxx miliseconds
it doesn't work like that... try .. I need some programers trick!
if I was in Pascal - I would have no trouble at all..


I did that a couple of times.. no, ****.. I did ##":"##,000 for the records
and then I expected to turn the cell that had the result in h:mm:ss,000...but the
thing was that I got 70 seconds for example and I needed Excel to write me 1min
10sec instead.. so I thought about mod() bla bla

And it had to be so trivial!! .. :)

Thanks!