Rewrite Permalink based on Metadata

Hi there,

Is it possible to rewrite the permalink for a basic post, similair to the way it has been done for a custom-post-type in the following code below?

I have event postings and do not wish for the permalink to show the post date, rather the actual event date.

I feel that custom post types are unnecessary for what I need- but would really like to be able to modify my permalinks based on custom meta…

add_action( 'init', 'create_calendar_type' );
function create_calendar_type() {
          register_post_type( 'calendar',
            array(
              'labels' => array(
                'name' => __( 'Events2' ),
                'singular_name' => __( 'Event2' )
              ),
              'public' => true,
              'rewrite' => array('slug' => 'events2/%cal_year%/%cal_month%/%cal_day%'),
              'show_ui' => true,
              'capability_type' => post,

            )
);
}

function calendar_link_filter( $post_link, $id = 0, $leavename = FALSE ) {
        $post = get_post($id);
        if($post->post_type != 'calendar') {
                return $post_link;
        }
        $date = get_post_meta($post->ID,'event_start_date',true);
        $date = strtotime($date);
        $str = $post_link;
        $str = str_replace('%cal_year%',date("Y",$date),$str);
        $str = str_replace('%cal_month%',date("m",$date),$str);
        $str = str_replace('%cal_day%',date("d",$date),$str);
        return $str;
}
add_filter('post_type_link','calendar_link_filter',1,3);