RSS Feed Localised Dates

Hi everyone,
I am having some hard times validating a custom RSS feed for a publication. My homepage uses a custom template which pulls articles from two different collections: #blog and #rivista (magazine in english) So I had to create also a custom RSS template for that page.

routes:
  /: home
  /rss/:
    template: home-rss
    content_type: text/xml

Since the publication language is set to Italian, the date helper renders the dates with italian month and day name:

<pubDate>{{date format="ddd, DD MMM YYYY HH:mm:ss ZZ"}}</pubDate>

     renders

<pubDate>dom, 05 lug 2020 17:55:15 +0200</pubDate>

That invalidates the whole feed and I can’t use anymore it to generate automatic RSS campaigns with Mailchimp.
https://validator.w3.org/feed/check.cgi?url=quadernopratese.it%2Frss%2F

Is there any way to force the data helper on English language? Or any workaround on the feed?
Thanks in advance for your help

Sidenote: the automatic generated RSSs such as http://quadernopratese.it/blog/rss/ render the dates in english and the feeds are correct.