This setting will prepend the premiered date to the episode title for "Upcoming Episodes" items only.  Skins tend to not use an addons assigned label passed via infoLabels for widgets and instead generate their own label using episode info.  Some skins do not show the premiered date for widgets so this comes in handy for those cases.  It's best to test this with your skin and widget settings in use.  It also respects the color highlight setting.