On Wed, Feb 7, 2018 at 12:22 PM Berry, Charles <ccberry@ucsd.edu> wrote:

Use an `eval' macro.

In a more recent version than you use, this works:

* abc
:PROPERTIES:
:EXPORT_TITLE: {{{etitle(my title)}}}
:END:

#+macro: etitle (eval (concat (format-time-string "%Y-%m-%d") " " $1))

That works for EXPORT_TITLE!

So I tried for EXPORT_FILE_NAME, but it doesn't work there, because org-export-output-file-name should be getting called internally *before* the macro expansion is done.