Google has added several new options to rearrange the results of a search. Many people, including me, have felt very limited by being unable to re-sort the results of a Google search, and remaining constrained only to Google's secret algorithm that determines the page rank/relevancy ranking. (For a deeper discussion of how Google works, see Full-Text and Search Engines in the AUR Library Information Wiki)
There is now a Show Options selection.
When you click on it, a menu appears where you can arrange your search in different ways, by Videos, Images, only those in the past hour, and so on.
The newest one they just instituted is a potentially useful one: the Timeline. You can refine by the date merely by clicking on the graphs. It is important to keep in mind that when you click on the date, it is still unclear exactly what Google is searching and displaying.
There is also the strange Wonder Wheel, which may also prove itself to be useful:
In any case, Google seems to be admitting that the single arrangement of search results may not be thoroughly adequate, so they are adapting to what people want.