No, that is not what I am looking for. I did see that selection but what I am looking for is a way of listing all posts that I have not yet read regardless of when they were posted.
Based on having a way to "Mark all forums read", I am assuming there is a way to view all that haven't been viewed yet. As an example, the Ambient Weather forum, which uses SMF forum software, has the ability to "Show unread posts since last visit" and if that fails to produce a listing, another link is shown "No unread topics found since your last visit. Click here to try all unread topics".
This kind of logic helps the user to find posts they have not read before even though they were not new since last login.