use strict;
use Data::Dumper;

my %list = (
    A => '1.13.04:Record:A',
    B => '1.12.04:Record:B',
    C => '3.13.04:Record:C',
);

my @sorted_date =
  map { $_->[0] }
  sort { $b->[1] <=> $a->[1] }
  map { my @n = /^(\d+)\.(\d+)\.(\d+):/;
        my $d = sprintf "%02d%02d%02d", @n[2,0,1];
        [join('.',@n), $d] } values %list;

print Dumper(\@sorted_date);

##</code><code>##

use strict;
use Data::Dumper;

my %list = (
    A => '1.13.04:Record:A',
    B => '1.12.04:Record:B',
    C => '3.13.04:Record:C',
    D => '3.13.02:Record:D',
);

my @sorted_date =
  map { [ $_->[1], $_->[0], $_->[2] ] }
  sort { $b->[1] <=> $a->[1] }
  map { my @n = $list{$_} =~ /^(\d+)\.(\d+)\.(\d+):/;
        my $d = sprintf "%02d%02d%02d", @n[2,0,1];
      	[join('.',@n), $d, $_] } keys %list;

my $month;
foreach (@sorted_date) {
  my $m = substr($_->[0], 0, 4); # retrieve YYMM
  if ($month ne $m) {
    print "</table>\n" if $month;
    $month = $m;
    print "<table>\n";
  }
  print "<tr><td>$_->[1]</td><td>HASH key: $_->[2]</td></tr>\n";
}
print "</table>\n" if $#sorted_date >= 0;

##</code><code>##

<table>
<tr><td>3.13.04</td><td>HASH key: C</td></tr>
</table>
<table>
<tr><td>1.13.04</td><td>HASH key: A</td></tr>
<tr><td>1.12.04</td><td>HASH key: B</td></tr>
</table>
<table>
<tr><td>3.13.02</td><td>HASH key: D</td></tr>
</table>