On 2025-06-18 05:06, Dan Juskevicius via tz wrote:
Dear sir or madam,
I'm currently working on an issue that one of our customers has reported with
the tz database. Using the latest release (2025b), I have been able to
reproduce an issue with America/Nuuk time where it reports at -02 instead of -01
Are these today's timestamps? If so, possibly QNX has trouble with TZif
version 3 format[1], as Brian mentioned. You might also check other time
zones that use version 3 format: these currently include Pacific/Easter,
America/Santiago, America/Scoresbysund, Asia/Jerusalem, Asia/Gaza, and
Asia/Hebron. To test this possibility, you can try compiling and testing
tzcode's zdump.c[2] on QNX with shell commands like this:
gcc -DUSE_LTZ=0 -o zdump zdump.c
./zdump -i -c 2025,2026 America/Nuuk
For America/Nuuk the zdump output should look like this:
TZ="America/Nuuk"
- - -02
2025-03-30 00 -01 1
2025-10-25 23 -02
If the output differs, it's almost surely a bug in QNX's C library,
which you can investigate.
Another possibility, if your customer is talking about timestamps
earlier this year, is that the customer incorrectly assumes that Nuuk
uses US rules for DST. Nuuk uses EU rules, which means that there are
roughly three weeks in March and one week in October/November where
America/Nuuk will correctly report -02 when a US-assuming customer would
expect -01.
By the way, thanks for letting us know that QNX was using TZDB. I
installed the attached patch to note this in our list.
[1]: https://datatracker.ietf.org/doc/html/rfc9636#section-3.3.2
[2]: https://raw.githubusercontent.com/eggert/tz/refs/heads/main/zdump.c
From 9dd68fcded7eca24f58033e0c71073a6de13a142 Mon Sep 17 00:00:00 2001
From: Paul Eggert <[email protected]>
Date: Thu, 19 Jun 2025 10:41:59 -0700
Subject: [PROPOSED] QNX is also downstream
* tz-link.html: Also mention QNX in the OS list.
---
tz-link.html | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tz-link.html b/tz-link.html
index 1a2070f5..229c9d8a 100644
--- a/tz-link.html
+++ b/tz-link.html
@@ -97,8 +97,9 @@ title="iPhone OS">iOS</abbr></a>,
<a href="https://www.microsoft.com/en-us/windows";>Microsoft Windows</a>,
<a href="https://www.vmssoftware.com";>Open<abbr
title="Virtual Memory System">VMS</abbr></a>,
-<a href="https://www.oracle.com/database/";>Oracle Database</a>, and
-<a href="https://www.oracle.com/solaris";>Oracle Solaris</a>.</p>
+<a href="https://www.oracle.com/database/";>Oracle Database</a>,
+<a href="https://www.oracle.com/solaris";>Oracle Solaris</a>,
+and <a href="https://blackberry.qnx.com/en";>QNX</a>.</p>
<p>
Each main entry in the database represents a <dfn>timezone</dfn>
for a set of civil-time clocks that have all agreed since 1970.
--
2.48.1
