Fantastic, c.gingerich. Yes, by "absolute" I mean it shouldn't matter which file is placed first or second, either can be newer or older, or the same.
Without absolute value, if newer file is placed first, the result would be a negative number.
I see no problem giving a negative number, if it makes programming any easier. But I'm guessing most people would like to simply see a positive number (absolute value).
By the way, regarding my request here, I am primarily interested in the TIME difference between the two files. In a single folder (subdirectory) output is being generated -- 16,000 files -- the whole process takes around three hours. I'd like to be able to see that total time taken by using such a program as I request -- put in the first-created file, and the last-created file, press enter, presto, roughly total time of the entire process.
There is an initial file in that folder that is from a "pre-process," with an earlier time/date. So simply grabbing the earliest date and the most recent date wouldn't give the desired answer.
Thanks a bunch!