The 'Today's Posts' function is listed on every forum page. It is NOT listed under 'whats new', 'blogs' or 'home'.
To get to 'Today's Posts' within one click - simply use the 'Forum' link in the top bar, and directly below it will be the 'Today's Posts' link.
If you're already within the boundaries of the forum (i.e. not the blog, not the articles, not the search function page, not the links directory - but reading a post, a thread, a sub forum or a private message screen) it will be listed at the top.