now sectionwise: date_converter: delta / time
Date converters used for testing the resolution of #4332

See also: #4631

See comment [here](https://github.com/pydata/pandas/issues/1180#issuecomment-31418130).

Sorry @timmie , I know your PRs haven't had much success with us so far.
 @timmie @y-p A suggestion, to not get this lost as this could be interesting for some users, it could maybe interesting to add this to the cookbook (instead of including it in pandas source code)? 
Most items there are links to anther page (mostly stackoverflow), so @timmie, if you could put the example somewhere online, you could add a link to that in the cookbook?
