Wikimedia Bugzilla is closed!

The use of an ISO week of the year variable is useful for lower-traffic sites
for elements such as a weekly featured article or collaboration of the week. The
range is 1-54 (ISO weeks begin on Monday, so most years have 53 weeks)

The magic word has been successfully implemented on SailWiki and involves the
following changes:

includes/magicwords.php - add MAG_CURRENTWEEK
includes/parser.php - add to getVariableValue:

  case MAG_CURRENTWEEK:
    return $varCache[$index] = $wgContLang->formatNum( date('W') );

languages/language.php - add to $wgMagicWordsEn array:

  MAG_CURRENTWEEK          => array( 1,    'CURRENTWEEK'            ),