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<title>Issue 3319: Properly reference specification of IANA time zone database</title>
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<p><em>This page is a snapshot from the LWG issues list, see the <a href="lwg-active.html">Library Active Issues List</a> for more information and the meaning of <a href="lwg-active.html#C++20">C++20</a> status.</em></p>
<h3 id="3319"><a href="lwg-defects.html#3319">3319</a>. Properly reference specification of IANA time zone database</h3>
<p><b>Section:</b> 30.11.1 <a href="https://wg21.link/time.zone.general">[time.zone.general]</a> <b>Status:</b> <a href="lwg-active.html#C++20">C++20</a>
 <b>Submitter:</b> Germany <b>Opened:</b> 2019-11-05 <b>Last modified:</b> 2021-02-25</p>
<p><b>Priority: </b>0
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++20">C++20</a> status.</p>
<p><b>Discussion:</b></p>
<p><b>Addresses <a href="https://github.com/cplusplus/nbballot/issues/340">DE 344</a></b></p>

<p>
This paragraph says 
</p>
<blockquote><p>
"27.11 describes an interface for accessing the IANA Time Zone database described in RFC 6557, &hellip;"
</p></blockquote>
<p>
However, RFC 6557 does not describe the database itself; it only describes the maintenance procedures 
for that database, as its title implies (quoted in clause 2).
<p/>
Proposed change:
<p/>
Add a reference to a specification of the database itself, or excise all references to the IANA
time zone database.
</p>
<p>
<b>Howard Hinnant:</b>
<p/>
We can not entirely remove the reference to IANA because we need portable <code>time_zone</code> 
names (e.g. "America/New_York") and definitions. However the NB comment is quite accurate and 
fixed with the proposed resolution.
</p>

<p><i>[2019-11 Status to Ready during Wednesday morning issue processing in Belfast.]</i></p>



<p id="res-3319"><b>Proposed resolution:</b></p>
<p>This wording is relative to <a href="https://wg21.link/n4835">N4835</a>.</p>

<ol>
<li><p>Modify 2 <a href="https://wg21.link/intro.refs">[intro.refs]</a> as indicated:</p>

<blockquote>
<p>
-1- The following documents are referred to in the text in such a way that some or all of their 
content constitutes requirements of this document. For dated references, only the edition cited 
applies. For undated references, the latest edition of the referenced document (including any 
amendments) applies.
<ol style="list-style-type: none">
<li><p>[&hellip;]</p></li>
<li><p><del>(1.2) &mdash; INTERNET ENGINEERING TASK FORCE (IETF). RFC 6557: Procedures for Maintaining 
the Time Zone Database [online]. Edited by E. Lear, P. Eggert. February 2012 [viewed 2018-03-26]. 
Available at https://www.ietf.org/rfc/rfc6557.txt</del></p></li>
<li><p>[&hellip;]</p></li>
</ol>
</p>
</blockquote>
</li>

<li><p>Modify 30.11.1 <a href="https://wg21.link/time.zone.general">[time.zone.general]</a> as indicated:</p>

<blockquote>
<p>
-1- 30.11 <a href="https://wg21.link/time.zone">[time.zone]</a> describes an interface for accessing the IANA Time Zone 
<del>d</del><ins>D</ins>atabase <del>described in RFC 6557,</del> that interoperates with 
<code>sys_time</code> and <code>local_time</code>. This interface provides time zone support to 
both the civil calendar types (30.8 <a href="https://wg21.link/time.cal">[time.cal]</a>) and to user-defined calendars. 
</p>
</blockquote>
</li>

<li><p>Modify section "Bibliography" as indicated:</p>

<blockquote>
<p>
The following documents are cited informatively in this document.
<ol style="list-style-type: none">
<li><p><ins>&mdash; IANA Time Zone Database. Available at 
<a href="https://www.iana.org/time-zones">https://www.iana.org/time-zones</a></ins></p></li>
<li><p>&mdash; ISO/IEC 10967-1:2012, <i>Information technology &mdash; Language independent arithmetic &mdash; 
Part 1: Integer and floating point arithmetic</i></p></li>
<li><p>[&hellip;]</p></li>
</ol>
</p>
</blockquote>
</li>
</ol>





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