title: Does UTC date string require the format specifier "Z" even if that string includes time offset?
body: <p>For instance,</p>
  <pre><code>const d = new Date(&quot;2012-08-20T15:00:00-07:00&quot;);
  </code></pre>
  <p><code>d</code> here is a <em>UTC</em> time with time offset = <code>07:00</code>. Does it still require <code>Z</code> like this <code>2012-08-20T15:00:00-07:00Z</code>? Is this correct?</p>
  <p>If I take this string with <code>Z</code> and parse it using <code>Date.parse()</code> method in JavaScript, it throws an error. Not sure what is wrong!</p>