title: ISO8601 Date Time format D3
body: <p>I'm trying to display a time stamp on my D3 line graph. My data is in JSON. The date looks like this: '2015-04-02T23:10:00'. Currently, it's being formatted like this: 
          var timeFormat = d3.time.format('%Y-%m-%dT%H:%M:%S');
  When on the graph, it is displayed in this way: 
          Mon Jun 29 2015 09:50:00 GMT-0500 (Central Daylight Time)</p>
  
  <p>I would like to be able to format it so it only shows the time. For example, 09:50:00. I've tried timeFormat to something different and that hasn't worked. Any suggestions would be appreciated. </p>