title: How to do a timeline graph similar to GitHub using D3?
body: <p>GitHub uses D3 library for its graphs but I can't find any sample similar to how GitHub deals with timeline.</p>
  
  <p>GitHub allows the user to select a particular period in time within the graph and then it shows data specific to that period.</p>
  
  <p>Any example of the "period selection" ("brush") with D3?</p>