Change RSS pubDate from event date

Hi!

I think I have the same question this person did.

I’ve included this code in my theme’s functions.php file:

function add_events_to_rss_feed( $args ) {
  if ( isset( $args['feed'] ) && !isset( $args['post_type'] ) )
    $args['post_type'] = array('post', 'tribe_events');
  return $args;
}

add_filter( 'request', 'add_events_to_rss_feed' );

Here’s the resulting RSS feed. An event I posted just this weekend shows up in the RSS feed with the event date, not the publish date:

<pubDate>Sat, 15 Apr 2017 23:00:00 +0000</pubDate>

As a result, MailChimp is sending newsletters every day between now and the event date. How do I change <pubDate> to the actual event date?

-Ken