Change Date Format in E-mails

I was looking at the issue reported at http://drupal.org/node/216018#comment-1920820 and left a comment there, but I'm thinking it may be best to open a different support request since that one was closed. The above issue dealt with Drupal 5, while I'm using Drupal 6.

I'm trying to change the date format in webform e-mails from mm/dd/yyyy to the format 'September 17, 2009'. I tried to override the function in my template.php page but it didn't work.

Here's what I have:

function phptemplate_webform_mail_date($data, $component) {
  $output = $component['name'] .':';
  if ($data[0] && $data[1]) {
    $timestamp = strtotime($data[0] .'/'. $data[1] .'/'. $data[2]);
    $format = webform_date_format('long');
    $output .= ' '. date($format, $timestamp);
  }

  return $output;
}

Is there a different way to accomplish this in Drupal 6?