[Zope-dev] Where to put stuff (ZCron)

I'm planning on adding a feature to Zope, called ZCron or somesuch, that'll run jobs on a regular basis, as with UNIX cron. Just so I don't reinvent the wheel, are there any similar that have been or are being done? Where is the right place to put it (in the source)? Regards, Morten W. Petersen