How can I delete nodes when an arbitrary date has past? I have a situation where future events will be posted to the website in question. These future events are a content type with a date field using the date module.

I wish to automatically delete these events once their date has past. I'm assuming that rules should do this but I have searched and I am struggling to find a way to do this.
You can use the hook_cron to solve your problem

function mymodule_cron(){
  _mymodule_delete_nodes();
}

function _mymodule_delete_nodes(){
  //select all nodes from type X where date expired
  //node_delete($nid);
}


See hook_cron for further information