hi xgreek.
This is not a hack but a Smarty plug-in.
get ryus_date plug-in from Ryuji's site.
http://ryus.biz/modules/mydownloads/viewcat.php?cid=3Copy modifier.ryus_date.php into YOUR_XOOPS/class/smarty/plugins/
Then, you can use modifier named ryus_date in template manager like this.
<{$topic.date|ryus_date:"new"}>