The SQL function usage would go directly in the query. Specifically around publish_up (e.g. DATE_FORMAT( `publish_up`, '%W %M %Y' ) AS publish_up_formatted).
i was thinking for the first question maybe the output of the php is related to languages files of Joomla?
Nope, it's localized directly by PHP. Joomla nor CB translate it. I'm not even sure if CB or Joomla could as again I haven't looked further into it yet. You may want to stick with strictly digit based displays for now if translations will be an issue for its display.