Deactivate post after certain date

Here is a little function that upon loading of site checks to see if the date is past the set date for that post id.  If so then it sets that post to draft mode and removes the post from the live site. Ideally this should be built on a cron job to run daily so that it doesn't have to fire with every webpage load but this should get you started.

function deactivate_post_check() {
    $post_ids = array('345' => '2017-08-15');
    $cur_date = new DateTime();
    if (count($post_ids) > 0) {
        foreach ($post_ids as $post_id => $date_value) {
            $shutoff_date = new DateTime( $date_value );
            $post_info = get_post( $post_id, 'ARRAY_A');
            if ($post_info['post_status'] == 'publish') {
                $post_info['post_status'] = 'draft';
                wp_update_post( $post_info );
            }
        }
    }
}

add_action('init', 'deactivate_post_check');