title: Identifying time zones in ISO 8601
body: <p>No, I'm not talking about zone offsets --- those can vary during the year for a region based on e.g. DST. I'm talking about the actual <a href="https://www.iana.org/time-zones" rel="noreferrer">time zones maintained by IANA</a>. I understand these are <em>not</em> supported by ISO 8601, correct?</p>
  
  <p>What are platforms doing to support identifying time zones in ISO 8601-like string representations? I notice that the latest Java date/time library is using an extended ISO 8601 format for this, e.g. <code>2011-12-03T10:15:30+01:00[Europe/Paris]</code>. (See <a href="https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html" rel="noreferrer">DateTimeFormatter API</a>.)</p>
  
  <p>Is there some converging convention (e.g. with other languages and platforms) for extending ISO 8601 to support time zone designation?</p>