Educational Question regarding Search database

I notice that the Search database was last updated on: Sat Sep 28 00:54:00 PDT 2002 ---- my general question is "How often is the search database updated?"

Thanks in Advance for your considerations and response.
Richard

Once a week if the system permits it. As you can see by the long downtimes DMOZ has lately, there are backend works going on. No guess when this may become normal again.

Thanks of the education and prompt response

Richard