This is a widgetised featured posts plugin that provides configurable links to posts that you want to highlight on your blog.
Ensure that there is no HTML markup in the post before the first sentence. HTML confuses Those Were The Days.
= I want a different time period You can quite easily add some new time periods into the function twtd_add_intervals() in those_were_the_days.php. You'll need some PHP programming skills but it's pretty straight forward.
= Plugin doesn't seem to be working Have you refreshed you blog as in step 5 of the installation instructions? ~ No, then go do that now!