I'm having an issue with a custom search form that doesn't filter results as I need it to. I need it to filter based on the date and/or category(s) selected.
code used within template:
<aside class="widget widget_filter">
<h4>FILTER SEARCH</h4>
<form method="get" action="<?php bloginfo('url'); ?>">
<input type="hidden" name="post_type" value="news" />
<?php $args = array(
'order' => 'DESC',
'orderby' => 'date',
'post_type' => 'news',
'posts_per_page' => '-1'
);
$counter = 0;
$ref_month = '';
$monthly = new WP_Query($args);
if( $monthly->have_posts() ) : ?>
<p>Date</p>
<select name="m">
<option value="">Please Select Date</option>
<?php while( $monthly->have_posts() ) : $monthly->the_post();
if( get_the_date('mY') != $ref_month ) : ?>
<option value="<?php the_date('Ym'); ?>"><?php echo get_the_date('F Y'); ?></option>
<?php $ref_month = get_the_date('mY');
$counter = 0;
endif;
endwhile; ?>
</select>
<?php endif; ?>
<?php wp_reset_postdata(); ?>
<p>Filed In</p>
<?php $terms = get_terms( 'news-category' );
foreach( $terms as $term ) : ?>
<label><input type="checkbox" name="cat" value="<?php echo $term->term_taxonomy_id ?>" /><?php echo $term->name; ?></label>
<?php endforeach; ?>
<input type="image" src="<?php echo get_stylesheet_directory_uri(); ?>/images/btn-filter.png" />
</form>
</aside>
If I select a date only it works fine and redirects to a url similar to website.dev/2013/09/?post_type=news&x=67&y=8
If I select a date and category it redirects to a 404 page with a url similar to website.dev/?post_type=news&m=&cat=7&x=88&y=21
I've tried changing the cat parameter to category and Wordpress ignores it. My .htaccess file is setup as Wordpress recommends and I've flushed DNS via the permalinks page in case that was an issue but this didn't resolve it.
How can I get it to filter by both parameters?
edit: Could it be due to it being a custom post type and custom taxonomy? I couldn't find what the correct parameter name would be to pass instead of 'cat'