The edition numbering on the Daily Roman Missal can be a bit confusing, because the Daily Roman Missal and the Roman Missal (Missale Romanum) have different edition numbers (currently the 7th and the 3rd respectively).
If you’re interested in all the details, we have an entire blog post about the edition numbering of the Daily Roman Missal. But the short answer is: we only sell the latest (7th) edition of the Daily Roman Missal. If you purchase from us, you are getting the latest and greatest!