title: D3 - get current time and subtract by 2 hours
body: <p>I'm trying to create two variables in d3, one that is the current hour &amp; minute (in 00:00 format) and one that is simply the current time with the hour value subtracted by two. So, for instance: current time is 15:38, the other variable would be calculated to be 13:38. </p>
  
  <p>Here's my current code for getting the current time (in coffeescript):</p>
  
  <pre><code>formatTime = d3.time.format("%H:%M")
  currentTime = (d) -&gt; formatTime(new Date())
  </code></pre>
  
  <p>Thanks in advance!</p>