[Mediawiki-l] Feature/variable question

[Amgine]

I'm trying to set up a main page with some elements similar to the 
Wikipedia, but would like to have a weekly featured article. 
{{CURRENTWEEK}} (giving the week of the year number 0-52) is not 
currently an available variable, but I suspect I could cobble together a 
method to calculate it, if I knew where in MediaWiki to stick it.

Is there any way to get the current week? if not, is there a text 
suggesting where/how to hack it in?

Amgine