A "New Visitor"'s first visit lasts as long as they are active. If the user is inactive for 30 minutes or longer, their session is reset, meaning that they will then become a "Return Visitor" upon their next visit or once they become active again after those 30 minutes of inactivity. This also means that if the visitor moves around the site every 29 for a whole day, they will be counted as a "New Visitor" that whole day, since their session was never reset (because they never went over the 30 minute threshold). Check out our article on New or Returning Visitor in our product documentation for more info. Hope this is helpful!