From the DivTag documentation:
updateFreq false false Number
How often to reload the content (in milliseconds). e.g. 5000
So it is there and it also has the same name.
You only need to change <sx:
to <sj:
, import jquery tags:
<%@ taglib prefix="sj" uri="/struts-jquery-tags" %>
and put <sj:head/>
in your <head>
section, where you should already have <sx:head/>