This sounds almost exactly like something I whipped up in the early 2000s [1]. Each post was its own directory (so I could just drop images in), and it used file system metadata for dates. It was based on Bash, ImageMagick, sed, m4, head, tr, and... XSLT (I swear it seemed like a good idea at the time!).

Believe it or not, the tool actually even worked with Cygwin after I switched to Windows (on my very first laptop).

[1] https://log.schemescape.com/posts/static-site-generators/pre...