I appreciate the response, Jkthemac. Sorry for the delay; I don't recall an auto-notification of your reply. Here's the goal. For ongoing series, I use count = 0 for all books in a series (an arbitrary choice). When I am certain that the series has ended, I'll change the count of all books in the series to "x," where x = the total number of books in the series. Occasionally, I can't be sure if a series has ended so that I know to change the count of books in the series from 0 to x (Example: six books in the series, with "dates added" roughly one month apart, where book no. 6's "date added" date is four months ago). I might reasonably assume that this series has ended because I know that I have not forgotten to any issues and no book has been added for, say more than 3 months and conclude that it's appropriate, therefore, to change the counts from 0 to x. Of course, I can create a simple smartlist to identify all books with 0 counts and examine the last book in each found series to see if that last book was added more than four months ago. In other words, I'd like a smartlist/script that would answer the single question "which ongoing series (for me, easy- those with 0 counts) have not had a book added for more than 4 months" and then exhibit all such complete series. If an inspection of the exhibited series revealed that books are generally added every 5 months, for example, I would perform a reality check before assuming the end of the series, but if books are added monthly, the series has likely ended. My apologies if I've over-complicated this.