As noted by my nickname, I am a Salesforce N00B (newbie) and I have some general questions re. what is and isn't possible in APEX.

Is it possible to change the owner of a Lead back to the general queue if there has been no activity against that lead for N days?

Example: 

John owns the ACME lead. John has not had any activity with ACME in the past 15 days. ACME's owner is then set to nobody so that others can pick that lead up. 

I'm not looking for triggers that update objects on CREATION or UPDATE...I'm looking for a solution that will change based on date.

As noted by my nickname, I am a Salesforce N00B (newbie) and I have some general questions re. what is and isn't possible in APEX.

Is it possible to change the owner of a Lead back to the general queue if there has been no activity against that lead for N days?

Example: 

John owns the ACME lead. John has not had any activity with ACME in the past 15 days. ACME's owner is then set to nobody so that others can pick that lead up. 

I'm not looking for triggers that update objects on CREATION or UPDATE...I'm looking for a solution that will change based on date.