title: Are time zone designators- "T" and "Z" case sensitive in ISO8601 format?
body: <p>I am using following ISO8601 format:</p>
  <pre><code>YYYY-MM-DDThh:mm:ssZ
  </code></pre>
  <p>And I used <code>OffsetDateTime.parse()</code> to parse this format. I was able to parse date-time by passing <code>t</code> (instead of <code>T</code>) and <code>z</code> (instead of <code>Z</code>) here.</p>
  <p>So can anyone tell if it is allowed in <strong>ISO8601</strong> or is it missed only in parsing logic?</p>