Sometimes I will be looking for an older article. Perhaps to you tech guys a VERY old article but to me it is just a blip (I live in the concept of the long now). And I cannot find it since there may be a new story or website that might have its very name as their title. For example, the act of couchsurfing existed long before the website couchsurfing came about (ie. hijacked the term). However, if I search for "couchsurfing" within the past day, month, year or decade all that is going to show for page after page is the actual site. I might want to see an article on it from 2004. You know what I mean? I have better examples but can't think of them at the moment. So to add date filters that allows you to search for articles dated within a certain time period, say March 2004 to August 2004 then you would be taking it a step further than even Google does. Watch them hijack this idea now.