title: what's an efficient way in swift to get a "change of day" event
body: <p>so I've a swift-ui app where I show information for the current day - so at midnight I want it to switch to a new day - trouble is I want this to be as &quot;light&quot; as possible - eg I don't want anything consuming any resources as all I want to do is refresh the view, if it's displayed.</p>
  <p>How do I do this without consuming background resources when the view isn't shown?</p>