Change blog url for Twitter button to save them sweet tweet counts

tweet-button.php

<h2>Twitter Button</h2>
  
  <?php
    /* bocoup.com was originally hosted across a number of subdomains. Since
    * then, it has switched to organizing content with subdirectories. Construct
    * the URL for the given item according to the site structure when the item
    * was first published.
    */
    
    function url_at_publication($id) {
      $weblogPath = '/weblog';
      $post = get_post($id);
      $subdomainRemovalDate = new DateTime('2014-04-25 00:00:00');
      $postDate = new DateTime($post->post_date);
      
      if ( $postDate < $subdomainRemovalDate ) {
        $url = 'http://weblog.bocoup.com/' . $post->post_name;
      }
      else {
        $url = 'http://bocoup.com/blog/' . $post->post_name;
      }
      return $url;
    }

  ?>
  
  <a href="https://twitter.com/share"
  class="twitter-share-button"
  data-hashtags="bocoup"
  data-text="<?php echo $post->post_title; ?> by <?php echo the_author_meta('display_name', $post->post_author); ?>"
  data-counturl="<?php echo url_at_publication($post->ID); ?>"
  >Tweet</a>
  <script>
  !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");
  </script>