I'm assuming you have something like this:

#               id day number
my @array = ( [  1, 25,  6156 ],
              [  2, 13,  5324 ],
              [  3, 32, 13617 ] );
[download]

In which case, you want to sort it thusly:

my @sorted_array = sort { $a->[1] <=> $b->[1] } @array;
[download]