WordPress: More Previous and Next Posts

<?php
/*
This is a function customization to get more than one previous and next post!
Original function can be found at https://core.trac.wordpress.org/browser/tags/4.0/src/wp-includes/link-template.php#L1465

Put the code below into your theme functions.php file.
*/

function wpmidia_get_adjacent_posts( $post_id = null, $limit = 1, $previous = true, $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
    global $wpdb;

    if ( ( ! $post = get_post( $post_id ) ) || ! taxonomy_exists( $taxonomy ) )
        return null;

    $current_post_date = $post->post_date;

    $join = '';
    $posts_in_ex_terms_sql = '';
    if ( $in_same_term || ! empty( $excluded_terms ) ) {
        $join = " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id";

        if ( $in_same_term ) {
            if ( ! is_object_in_taxonomy( $post->post_type, $taxonomy ) )
                return '';
            $term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
            if ( ! $term_array || is_wp_error( $term_array ) )
                return '';
            $join .= $wpdb->prepare( " AND tt.taxonomy = %s AND tt.term_id IN (" . implode( ',', array_map( 'intval', $term_array ) ) . ")", $taxonomy );
        }

        $posts_in_ex_terms_sql = $wpdb->prepare( "AND tt.taxonomy = %s", $taxonomy );
        if ( ! empty( $excluded_terms ) ) {
            if ( ! is_array( $excluded_terms ) ) {
                if ( false !== strpos( $excluded_terms, ' and ' ) ) {
                    _deprecated_argument( __FUNCTION__, '3.3', sprintf( __( 'Use commas instead of %s to separate excluded terms.' ), "'and'" ) );
                    $excluded_terms = explode( ' and ', $excluded_terms );
                } else {
                    $excluded_terms = explode( ',', $excluded_terms );
                }
            }

            $excluded_terms = array_map( 'intval', $excluded_terms );

            if ( ! empty( $term_array ) ) {
                $excluded_terms = array_diff( $excluded_terms, $term_array );
                $posts_in_ex_terms_sql = '';
            }

            if ( ! empty( $excluded_terms ) ) {
                $posts_in_ex_terms_sql = $wpdb->prepare( " AND tt.taxonomy = %s AND tt.term_id NOT IN (" . implode( $excluded_terms, ',' ) . ')', $taxonomy );
            }
        }
    }

    $adjacent = $previous ? 'previous' : 'next';
    $op = $previous ? '<' : '>';
    $order = $previous ? 'DESC' : 'ASC';

    $join  = apply_filters( "get_{$adjacent}_post_join", $join, $in_same_term, $excluded_terms );

    $where = apply_filters( "get_{$adjacent}_post_where", $wpdb->prepare( "WHERE p.post_date $op %s AND p.post_type = %s AND p.post_status = 'publish' $posts_in_ex_terms_sql", $current_post_date, $post->post_type), $in_same_term, $excluded_terms );

    $sort  = apply_filters( "get_{$adjacent}_post_sort", "ORDER BY p.post_date $order LIMIT $limit" );

    $query = "SELECT p.ID FROM $wpdb->posts AS p $join $where $sort";
    $query_key = 'adjacent_post_' . md5( $query );
    $result = wp_cache_get( $query_key, 'counts' );
    if ( false !== $result ) {
        if ( $result )
            $result = array_map( 'get_post', $result );
        return $result;
    }

    $result = $wpdb->get_col( $query );
    if ( null === $result )
        $result = '';

    wp_cache_set( $query_key, $result, 'counts' );

    if ( $result )
        $result = array_map( 'get_post', $result );

    return $result;
}

/*
Usage: ATTENTION: THIS IS A SAMPLE CODE! CHANGE IT FOR YOUR PURPOSE...
Put the code below where you want to show de list of posts
TIP: You can use print_r() to see what the function is bringing.....

PARAMTERS:
$post_id = The ID of the actual post
$limit = Number of posts you want
$previous = If true, it shows the previous posts list. If false, it shows the next posts list.
...
*/

echo '<h2>Previous posts</h2>';
$previous = wpmidia_get_adjacent_posts(19, 3);  // CHANGE THE ID AND NUMBER OF POSTS

if( $previous ){

    echo '<ul>';

    foreach( $previous as $prev ){

        echo '<li>[' . mysql2date('d/m/Y', $prev->post_date) . '] ' . $prev->post_title . '</li>';

    }
    echo '</ul>';

}

echo '<h2>Next posts</h2>';
$next = wpmidia_get_adjacent_posts(19, 3, false); // CHANGE THE ID AND NUMBER OF POSTS

if( $next ){

    echo '<ul>';

    foreach( $next as $nextpost ){

        echo '<li>[' . mysql2date('d/m/Y', $nextpost->post_date) . '] ' . $nextpost->post_title . '</li>';

    }
    echo '</ul>';

}

?>