From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.2 required=5.0 tests=BAYES_00,FREEMAIL_FROM,
	FROM_STARTS_WITH_NUMS autolearn=no autolearn_force=no version=3.4.4
X-Received: by 2002:a0c:c2d4:: with SMTP id c20mr6582905qvi.246.1588447517508;
        Sat, 02 May 2020 12:25:17 -0700 (PDT)
X-Received: by 2002:a05:6830:1058:: with SMTP id
 b24mr8596272otp.16.1588447517163;
 Sat, 02 May 2020 12:25:17 -0700 (PDT)
Path: 
 eternal-september.org!reader01.eternal-september.org!feeder.eternal-september.org!news.gegeweb.eu!gegeweb.org!usenet-fr.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: comp.lang.ada
Date: Sat, 2 May 2020 12:25:16 -0700 (PDT)
In-Reply-To: <r8k45t$1s0r$1@gioia.aioe.org>
Complaints-To: groups-abuse@google.com
Injection-Info: google-groups.googlegroups.com;
 posting-host=2001:8b0:ca:2:0:0:0:fd;
 posting-account=TiHetgoAAACluCgYkPc8-TWs6dBNgSne
NNTP-Posting-Host: 2001:8b0:ca:2:0:0:0:fd
References: <4f7d162e-356c-4cc4-abc3-f4cfe195b9cd@googlegroups.com>
 <r8bg8g$h6f$1@gioia.aioe.org>
 <9dad342a-7981-4d09-a414-7cec651097ac@googlegroups.com>
 <r8clv2$mic$1@gioia.aioe.org>
 <ff1dabc9-db8c-483a-8a54-b1c2978fc7cf@googlegroups.com>
 <r8feu5$1o0b$1@gioia.aioe.org>
 <f52d4d39-757e-46e0-af0b-27d9aedc5ed4@googlegroups.com>
 <a17e3e50-de03-474f-af6e-be68caa94873@googlegroups.com>
 <r8k45t$1s0r$1@gioia.aioe.org>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <c1a7b8fe-75bf-4904-9b54-16bb30b9592c@googlegroups.com>
Subject: Re: Getting the 3 letter time zone abbreviation
From: Bob Goddard <1963bib@googlemail.com>
Injection-Date: Sat, 02 May 2020 19:25:17 +0000
Content-Type: text/plain; charset="UTF-8"
Xref: reader01.eternal-september.org comp.lang.ada:58557
Date: 2020-05-02T12:25:16-07:00
List-Id: <comp.lang.ada>

On Saturday, 2 May 2020 16:38:43 UTC+1, Dmitry A. Kazakov  wrote:
> On 2020-05-02 17:08, Bob Goddard wrote:
> > And apparently this will not work on non BSD/Linux system, as we need access to the external var tzname, which, if going by the similarly external errno, would require a small C program.
> > 
> > Unless someone knows how to get access to arbitrary external vars.
> 
> http://ada-auth.org/standards/12rm/html/RM-A-17.html
> 
> > Still, there is no reason why this could not be implemented in GNAT.
> 
> You can propose an AI for the incoming standard.

RM-A-17 is for environmental vars, rather than external, ie library or system ones;

Anyway, turns out Windows does not support the IANA 3/4 letter tz database.

Calling tzset and examining the returned array, returns a string similar to "New Zealand Daylight Time".

tzset, at least on Linux, and I assume every other unix type system which uses the tz data base does return the 3/4 letter tz name.

Ho hum!