Sorry, I´m not so familar with the new phpBB 3.x forum script.
There are many MODs on this website, but I have found nothing, you want to have (although it was possible in phpBB 2.x).
But in version 3.x they have added two links on top of the forum ("view new posts" and "view active topics").
When you click the link "view new posts", you will see all new posts since your last login.
When you click the link "view active topics", you will get a list of all active topics in the last days. Below the list you may choice how many topics will be displayed (from 1 day to 1 year).
Sorry, thats all I can tell you in the moment.
Mario