Wordpress Date.php returns only five posts and many empty posts

Question

I am implementing a monthly archive in wordpress, and so am using the date.php file to display posts per month. In this file I have some paging code to get the month and date, but my Loop only ever displays five posts and includes many empty posts, if I do paging, with say 3 posts per page, the total pages is still 5 even though the paging works. In addition to this, the result contains many empty posts (by which I mean it has no fields, but the_title returns 1. January 1979).

My loop looks like this (nevermind the external bit - its a custom field to determine if the whole post is stored externally):

$current_page = max(1, get_query_var('paged'));
$posts = get_posts('cat=19,20&posts_per_page=3&monthnum='.$m.'&year='.$y.'&paged='.$current_page);
    if ( have_posts() ) {
        while ( have_posts() ) {
            the_post(); 
            //
            // Post Content here
            ?>

<?php $externalLink = do_shortcode('[cft key=external before_list="" after_list="" before_value="" after_value=""]');  ?>
<?php if( strlen($externalLink) <= 1): ?>
                            <div class="title">
                            <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a>
                            <div class="time small">
                            <?php if(get_the_time('Y') != '1970') the_time('F jS, Y'); //the_category('','multiple'); ?>
                            </div>
                            </div>
<?php else: ?>
                            <div class="title">
                            <a href="<?php echo $externalLink ?>" target="_blank" rel="bookmark" title="External Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a>
                            <div class="time small">
                            <?php if(get_the_time('Y') != '1970') the_time('F jS, Y'); // the_category('','multiple');?>
                            </div>
                            </div>
<?php endif; ?>            

<?php
        } // end while
    } // end if
?>

The whole code including the paging logic is found here: https://gist.github.com/uansett/fd1183216ab980e1279a#file-date-php

Answer 1

get_posts doesn't replace the posts WordPress has already selected for the page. You'd need something like (untested):

$posts = get_posts('cat=19,20&posts_per_page=3&monthnum='.$m.'&year='.$y.'&paged='.$current_page);
foreach ( $posts as $post ) : setup_postdata( $post ); ?>
    // Your code
<?php endforeach; 
wp_reset_postdata(); // If you still want to access the originally selected posts ?>

Failing that you could use query_posts, which does replace the posts WordPress has selected. Though the codex generally advises against using query_posts:

TL;DR don't use query_posts() ever;