sum of the result from the formula?

[Bel]

Dear Friedns,
In sheet 1, the format like this:
A B
1. 12:00 pm 8:00 pm
2.12:30 pm 8:00 pm
In sheet 2, I wrote the formula: =text(B-A, "h:mm") get the hours: 8.
My question is: when I write the formula for SUM( A1:A2). It comes out zero.
Also, some times I put off when employee does not come work. In sheet, it
will come"#VALUE!". If I wanna sum function, how I can skip these cells
with"#VALUE!"? Thank you very much in advance.

 

[Peo Sjoblom]

It's because you are using text, just use

=B-A

then

=SUM(Range)

and format as [hh]:mm



Regards,

Peo Sjoblom