Display content between two dates?

by 

<?php <br />
 function filter_where($where="") {<br/>
$where .= " AND post_date >= '1980-05-11' AND post_date <= '2011-05-11'";<br/ >
    return $where;</br>
  }<br/>
add_filter('posts_where', 'filter_where');<br/>
query_posts($query_string);<br/>
while (have_posts()) :<br/>
      the_post();<br/>
      the_content();<br/>
endwhile;<br/>
?>

get meta data value and replace with the numeric date.