title: Find element by class and custom attribute value (then update it)
body: <p>Using jQuery I want to add some HTML to a specific <code>&lt;td&gt;</code> whose attribute matches the value I have. </p>
  
  <p>For example I have a value '2015-02-01', I want to find/search the <code>&lt;td&gt;</code> which had the attribute 'data-date="2015-02-01"' and append HTML to the matched value, which in this example is <code>&lt;td&gt;1&lt;/td&gt;</code></p>
  
  <pre><code>&lt;div class="fc-content-skeleton"&gt;
  &lt;table&gt;
  &lt;thead&gt;
  &lt;tr&gt;
  &lt;td data-date="2015-02-01" class="fc-day-number"&gt;1&lt;/td&gt;
  &lt;td data-date="2015-02-02" class="fc-day-number"&gt;2&lt;/td&gt;
  &lt;td data-date="2015-02-03" class="fc-day-number"&gt;3&lt;/td&gt;
  &lt;td data-date="2015-02-04" class="fc-day-number"&gt;4&lt;/td&gt;
  &lt;td data-date="2015-02-05" class="fc-day-number"&gt;5&lt;/td&gt;
  &lt;td data-date="2015-02-06" class="fc-day-number"&gt;6&lt;/td&gt;
  &lt;td data-date="2015-02-07" class="fc-day-number"&gt;7&lt;/td&gt;
  &lt;/tr&gt;
  &lt;/thead&gt;
  &lt;/table&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I dont have any sample code as I am stuck really on how to approach this.</p>
  
  <pre><code>// This only gives me the value of the attribute
  $this.parent().find('.fc-day-number').attr('data-date');
  </code></pre>