Having trouble querying posts in the loop

Hi,

I’ve created a plugin which adds a custom post type (programmes) with some custom meta. I’m now trying to create a shortcode which displays programmes if their broadcast-date (custom meta) is greater than or equal to today’s date.

I’m working on a local install so I can’t post a link, but I’ve posted the code I’m using below. The broadcast-date uses the html datepicker input and is rendered on the page in YYYY-MM-DD format (although in the input field it shows DD/MM/YYYY), so I’ve tried both formats in a php variable with today’s date to compare it with, but it returns all the programmes, regardless of date.

add_shortcode( 'my-schedule', 'my_schedule_shortcode' );
function my_schedule_shortcode( $atts ) {
    $todaysDate = date("Y-m-d"); // I've tried date("d-m-Y") too
    ob_start();
    $query = new WP_Query(array(
	'post_type' => 'programmes',
	'meta_query' => array(
	    array(
		'orderby' => 'broadcast-date',
		'key' => 'broadcast-date',
		'value' => $todaysDate,
		'compare'   => '>='
	    ),
	),
    ));
    if ( $query->have_posts() ) {
	?>
        <div class="schedule-container" >
            <?php while ( $query->have_posts() ) : $query->the_post();
	    $programmeImage = wp_get_attachment_url( get_post_thumbnail_id($post->ID, 'thumbnail') );
	    $programmeBroadcastDate = get_post_custom_values('broadcast-date', $post->ID);
	    ?>
            <div id="programme-<?php the_ID(); ?>" <?php post_class(); ?> style="background-image: url( <?php echo $programmeImage ?> )">

		<div class="schedule-titlebar">
		    <h3><?php the_title(); ?></h3>
		    <p><?php echo $programmeBroadcastDate[0] ?></p>
		</div>

		<div class="schedule-description">
		    <?php the_excerpt(); ?>
		</div>

		<a class="schedule-link-overlay" href=" <?php the_permalink(); ?> " title=" <?php the_title(); ?> " ></a>

            </div>
            <?php endwhile;
            wp_reset_postdata(); ?>
        </div>
	<?php $myvariable = ob_get_clean();
	return $myvariable;
    }

}

Any ideas?

Thanks