the percentage of a JS date object within a range
<p>I have three date objects.  How do I go about comparing them such that I can determine the relative disparity between them.</p>

<pre><code>oldDate = newDate() - 5;
midDate = newDate() - 2.5;
newDate = newDate();
</code></pre>

<p>What percentage would midDate be between the two?</p>