Thanks, bunyip, I'm getting warmer thanks to your help.

I found the date_long function, which referenced another constant DATE_FORMAT_LONG in english.php. That's where the formatting is, so I can tweak that as needed.

So many constants in so many files!

As for FILENAME_PRODUCTS_ALL - it's not in my includes/filenames.php, maybe that's why my link is broken?

We seem to be using different ZC versions (I'm 3.0) because none of the line numbers you've provided match mine - no big deal, since control-F does the job, but that may be why my code isn't where yours is?