get wordpress post loop by meta box date

Have you tried passing in the $args variable to query_posts, rather than $guide?

query_posts($args);

Also, you should be looking to create the custom query using WP_Query class and not the query_posts. See this answer for more details (https://wordpress.stackexchange.com/a/1755)

Try the below code:

$args = array('post_type'  => 'post', 'meta_key' => 'meta_date', 'meta_value_num' => , );

$my_query = new WP_Query( $args );

if($my_query->have_posts() { 
    while($my_query->have_posts()) : $my_query->the_post();
          echo get_the_title();
    endwhile;
}

Also, please see the following: Order custom posts by a date metabox.