title: Custom multi-scale time formats in d3
body: <p><code>d3.time.scale</code> has a neat time formatter which uses <a href="https://github.com/mbostock/d3/wiki/Time-Scales#wiki-tickFormat" rel="nofollow">multi-scale time formats</a>. Is there an API or other way (yet) to specify a <a href="https://github.com/mbostock/d3/wiki/Time-Scales#wiki-tickFormat" rel="nofollow">multi-scale time formats</a>? </p>
  
  <p>I know it is possible to create a new <code>d3.time.format</code>, but that won't be multi-scale.</p>
  
  <p>Thanks.</p>