Boris,
Sorry to take so long to respond.
Do you mean that you want start time and end time as opposed to start time and duration, which SV normally exports?
If so, then I'm afraid I can't think of a way to do this using SV at the moment -- but it's a good candidate for an additional feature, if you would like to submit a feature request using the SourceForge tracker.
In the mean time, one could always convert the files using an external tool. To take the immortal example of Perl:
$ cat test.txt
1.223 2.1543 sourceA
2.542 14.133 sourceB
3.161 0.041 sourceC
$ cat rewrite.pl
while (<>)
{
my ($a,$b,$c) = split /\s+/;
$b = $a + $b;
print join " ", ($a,$b,$c), "\n";
}
$ perl rewrite.pl test.txt
1.223 3.3773 sourceA
2.542 16.675 sourceB
3.161 3.202 sourceC
$
Chris