According to Eric O'Brien:
time I want to update my test server. I only want to process the files that have *changed* since the last time I ran the process. Conceptually, I sorta would like to work rsync into the process here, but I don't quite see how to do it (as none of the html files in the static site are going to match with their "source" php files).
Use make, that's exactly its "reason d'ĂȘtre".
.php.html: php ${.OODATE} > html/${.TARGET}
(in BSD make, GNU has a somewhat different syntax)