Before you click on a thread, you can read underneath it's title says who started the thread and when. If you've already clicked on the thread, the little green bar above each post has the date on the left side (or the elapsed time if it is a recent post, like "1 hour ago" or "2 days ago"

also, newer threads appear on the first page of the subforum, with the threads getting progressively older the farther back you go into the pages.