I stand corrected! I did not do a benchmark test with exhaustive input...
and you came up with an even faster method to boot... chapeau!

edit, new version, 2% faster:

        'newB' => sub {
            for my $time (@ps) {
                my @mult = (1, 60, 3600);
                my $age = $time =~ s/^(\d+)-// ? $1 * 86400 : 0;  # ag
+e in seconds
                $age += $_ * shift @mult for reverse split /:/, $time;
            }
        },
[download]