[Zope] Importable Xron

I want to use the Xron product but I don't understand how to use it. (http://www.zope.org/Members/lstaffor/Xron/) All this Zope Zen jargon makes me dissy. What I don't understand is where and why to put reschedules at certain places. Subclasses and DTML Methods...etc. Can you please include a importable zexp on the download page of Xron. I want to do one single simple thing for now. Send the <dtml-var webmaster> constant information about various site stats. These should be sent weekly or hourly or monthly. I also want to have more than one instance of Xron. Can somebody give me examples. Especially how you set the date and time. (I have no experience of cron and I live in GMT+0) Grateful, Peter Peter Bengtsson - OD Consultancy