BUU's reply is how I'd do it, but he forgot to rewrite the date in slashed format:

print "date\tversion\n";
for (0..$#dateArray) {
    my $date = $dateArray[$_];
    $date =~ s!^(\d\d)(\d\d)(\d\d)$!$1/$2/$3!;
    print "${date}\t$versionArray[$_]\n";
}
[download]

I didn't alter the original array, just a copy of each element as it came up. There might be reason to get old-fashoned and look at perlform, or modern and Template Toolkit.