Keeping content fresh

[John Martyniak]

How does nutch determine when content needs to be re-fetched?  The way  
that I understand it is that it is "next fetch" date which 7 days in  
the future.

Is there anyway to change that?  Or to increase the fetching  
interval.  Or somehow base it on how many times a piece of content is  
requested.

I would like to keep the content as fresh as possible, and the  
information changes more frequently than every 7 days.

Thanks in advance,

-John