How do I format the postamble in HTML-export with Org-mode?

Question

I am creating a website with org-mode and would like to format the postamble so it just shows the date created and the creator at the bottom of the page, in the center, and is h

Answer 1

The reason it isn't accepting your own postamble is because you have to use #+BIND: syntax for the variable so that it is used on export. (See Export Options)

After changing that setting I also had to adjust your format slightly to fit the required syntax. The default value for org-export-html-postamble-format is:

(("en" "
Author: %a (%e)
Date: %d
Generated by %c
%v
"))

So you'd have to do the following to have it included (matching as closely as possible to that format):

(setq org-export-html-postamble-format 
      '(("en" "
Last Updated %d. Created by %c
")))

This however will not center your text, it exports as follows:

Last Updated 2012-03-16 16:22:03 Eastern Daylight Time. Created by Org version 7.8.03 with Emacs version 24

I believe you'd have to set up a custom stylesheet with p.postamble { text-align: center; } to get the centering to work.