When a user is not logged in and acts as a guest clicking to "What's New?" leads to the list of new posts aged one day.
But when you've logged in and act as a user clicking to the same button "What's New?" leads to the lists of posts appeared only after your login time and there is no way get the list of the last day's posts.

By the way, is it possible to get the list of last week's posts like it was in the old forum with "active topics" link. (Plea-ea-ea-ease!)