From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/11750 Path: news.gmane.org!.POSTED!not-for-mail From: Natanael Copa Newsgroups: gmane.linux.lib.musl.general Subject: Re: [PATCH] use UTC instead of GMT Date: Fri, 28 Jul 2017 14:35:10 +0200 Message-ID: <20170728143510.692c5020@ncopa-desktop.copa.dup.pw> References: <20170722091903.19432-1-ncopa@alpinelinux.org> <20170722142625.GU1627@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1501245337 11505 195.159.176.226 (28 Jul 2017 12:35:37 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 28 Jul 2017 12:35:37 +0000 (UTC) Cc: musl@lists.openwall.com To: Rich Felker Original-X-From: musl-return-11763-gllmg-musl=m.gmane.org@lists.openwall.com Fri Jul 28 14:35:31 2017 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1db4UI-0002Ox-Vl for gllmg-musl@m.gmane.org; Fri, 28 Jul 2017 14:35:27 +0200 Original-Received: (qmail 31917 invoked by uid 550); 28 Jul 2017 12:35:30 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 31890 invoked from network); 28 Jul 2017 12:35:29 -0000 In-Reply-To: <20170722142625.GU1627@brightrain.aerifal.cx> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-alpine-linux-musl) Xref: news.gmane.org gmane.linux.lib.musl.general:11750 Archived-At: On Sat, 22 Jul 2017 10:26:25 -0400 Rich Felker wrote: > On Sat, Jul 22, 2017 at 11:19:03AM +0200, Natanael Copa wrote: > > GMT is a timezone officially used by some countries in Europe and > > Africa. UTC is not a timezone, but a time standard. No country or > > territory officialy uses UTC as local time. > > > > Also, POSIX mentions UTC a few places[1][2] but never GMT (except as an > > example[2] for a timezone) > > > > So it makes more sense to use UTC instead of GMT and return UTC when no > > timezone is set in /etc/localtime or TZ is set to empty. > > > > [1]: http://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime.html > > [2]: http://pubs.opengroup.org/onlinepubs/9699919799/functions/timezone.html > > --- > > > > This causes real problems for people: > > https://github.com/gliderlabs/docker-alpine/issues/310#issuecomment-316732179 > > The motivation for the naming was that POSIX "UTC" is not actually UTC > but something like UT1 or modified UTC more akin to historical GMT. Do you have any references on that? > You can certainly get it to show "UTC" just by setting TZ=UTC, but > if users are actually hitting problems from this it should be reviewed > whether the behavior still makes sense. The problem at hand seems to be that some docker image used hardcoded timezone to EST so they added automatic tests to verify that timezone is UTC. So tests broke on Alpine. To fix that it seems like they set the timezone via TZ=UTC variable, and that broke things for users who set the timezone via /etc/localtime. Basically lot of minor fuzz, which all can easily be worked around, but its just annoying. I checked what FreeBSD, OpenBSD and GNU/Linux does when timezone is unset. Seems that they all use "UTC" so I think that makes most sense. > > Rich