<p dir="auto">Challenge <a href="http://beta.freecodecamp.com/en/challenges/data-visualization-with-d3/change-styles-based-on-data" rel="nofollow">change-styles-based-on-data</a> has an issue.<br>
User Agent is: <code class="notranslate">Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.110 Safari/537.36</code>.<br>
Please describe how to reproduce this issue, and include links to screenshots if possible.</p>
<p dir="auto">It isn't the particular challenge but more so with how these challenges' tests evaluate the solutions. If you change the name of the variable, in this case dataset, to anything else (that you haven't already used in previous d3 challenges) the solution works.</p>
<p dir="auto">Even if you go back to the previous challenge (that passed), and submit again, it will respond that the variable has already been declared.  I had the same issue with mobile on android 6.0 using chrome 56.</p>
<div class="highlight highlight-text-html-basic notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="

&lt;body&gt;
  &lt;script&gt;
    const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
    
    d3.select(&quot;body&quot;).selectAll(&quot;h2&quot;)
      .data(dataset)
      .enter()
      .append(&quot;h2&quot;)
      .text((d) =&gt; (d + &quot; USD&quot;))
      // Add your code below this line
      
      
      
      // Add your code above this line
  &lt;/script&gt;
&lt;/body&gt;
"><pre class="notranslate"><span class="pl-kos">&lt;</span><span class="pl-ent">body</span><span class="pl-kos">&gt;</span>
  <span class="pl-kos">&lt;</span><span class="pl-ent">script</span><span class="pl-kos">&gt;</span>
    <span class="pl-k">const</span> <span class="pl-s1">dataset</span> <span class="pl-c1">=</span> <span class="pl-kos">[</span><span class="pl-c1">12</span><span class="pl-kos">,</span> <span class="pl-c1">31</span><span class="pl-kos">,</span> <span class="pl-c1">22</span><span class="pl-kos">,</span> <span class="pl-c1">17</span><span class="pl-kos">,</span> <span class="pl-c1">25</span><span class="pl-kos">,</span> <span class="pl-c1">18</span><span class="pl-kos">,</span> <span class="pl-c1">29</span><span class="pl-kos">,</span> <span class="pl-c1">14</span><span class="pl-kos">,</span> <span class="pl-c1">9</span><span class="pl-kos">]</span><span class="pl-kos">;</span>
    
    <span class="pl-s1">d3</span><span class="pl-kos">.</span><span class="pl-en">select</span><span class="pl-kos">(</span><span class="pl-s">"body"</span><span class="pl-kos">)</span><span class="pl-kos">.</span><span class="pl-en">selectAll</span><span class="pl-kos">(</span><span class="pl-s">"h2"</span><span class="pl-kos">)</span>
      <span class="pl-kos">.</span><span class="pl-en">data</span><span class="pl-kos">(</span><span class="pl-s1">dataset</span><span class="pl-kos">)</span>
      <span class="pl-kos">.</span><span class="pl-en">enter</span><span class="pl-kos">(</span><span class="pl-kos">)</span>
      <span class="pl-kos">.</span><span class="pl-en">append</span><span class="pl-kos">(</span><span class="pl-s">"h2"</span><span class="pl-kos">)</span>
      <span class="pl-kos">.</span><span class="pl-en">text</span><span class="pl-kos">(</span><span class="pl-kos">(</span><span class="pl-s1">d</span><span class="pl-kos">)</span> <span class="pl-c1">=&gt;</span> <span class="pl-kos">(</span><span class="pl-s1">d</span> <span class="pl-c1">+</span> <span class="pl-s">" USD"</span><span class="pl-kos">)</span><span class="pl-kos">)</span>
      <span class="pl-c">// Add your code below this line</span>
      
      
      
      <span class="pl-c">// Add your code above this line</span>
  <span class="pl-kos">&lt;/</span><span class="pl-ent">script</span><span class="pl-kos">&gt;</span>
<span class="pl-kos">&lt;/</span><span class="pl-ent">body</span><span class="pl-kos">&gt;</span></pre></div>
<p dir="auto">The last 2-3 days my activity calendar is blank. It shows no activity although it says i have completed 217 items so far.<br>
When i open chrome's console it has an error that might help in solving the problem which says "Uncaught TypeError: Cannot read property 'getTime' of undefined".</p>
<p dir="auto">I tried to open the page with firefox which i rarely used but never with freeCodeCamp in case it was a cache problem but still didn't work.</p>
<p dir="auto">I attached the screenshot below for your convenience.</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/15311969/11171275/e29f156a-8bf4-11e5-8569-ea913bd3fbec.jpg"><img src="https://cloud.githubusercontent.com/assets/15311969/11171275/e29f156a-8bf4-11e5-8569-ea913bd3fbec.jpg" alt="freecodecamp screenshot" style="max-width: 100%;"></a></p>