Here is the rejection part of my scheduled job. I just run this early in the morning each day.

var gr = new GlideRecord('sysapproval_approver');

var querystring = "state=requested^sysapproval.sys_class_name=sc_req_item^sys_updated_onRELATIVELT@dayofweek@ago@14";

gr.addEncodedQuery(querystring);

gr.query();

while (gr.next()) {

 gr.state = 'rejected';

 gr.comments = "Automatically rejected after 16 or more days of inactivity";

 gr.update();

}