Wondering if it would be possible to add an "older than" option (just to the advanced search page) ... I have had need in the past to track down old posts and if the search term is common enough, usually they are buried so far back in the results that you effectively can't find them.
It might also be useful to be able to order by "oldest" as well.
I assume there is a maximum number of search results returned - as such, it becomes effectively impossible to search for relatively frequent terms from posts older than a certain date, since there is currently no way of limiting the search results to posts sufficiently old to actually include them in the results.