Since the SORT issue is resolved by previous commentators - here is my $0.02 towards perl style and object design:

First ++ ysth on making the "perlish" loop. Here is a way to get rid of the extra array copy/intermediate/unnecessary variable " @items" for the same code segment:

for my $hashref (@{$self->{Items}}) {
  my $d = Dumper($hashref);
  print "$d\n";
#  my $date = $hashref->{Date};
}
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AN additional option is that your "new" method could allow for early loading of the structure if it replaced "$self->{Items} = ();" with the following lines:

 my $file = shift();
 if ($file){
   $self->set_items($file);
 }else{
   $self->{Items} = ();
 }
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This allows you the option of calling the "new" function like this:

my $list = new List($file);
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