use strict;

my @dates = qw{
     10/02/2004
     02/01/2004
     01/02/2004
     08/18/2010     
     01/06/2004
     01/02/2005
     01/12/2004
    };

my @sorted=
    map { substr $_, 8 }
    sort
    map { join q{}, ( split m{/} )[ 2, 0, 1 ], $_ }@dates;