From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Armstrong Subject: Re: Time-zone in dates Date: Tue, 7 Jul 2015 12:14:31 -0500 Message-ID: <20150707171431.GH6137@geta> References: <87ioaav72g.fsf@ucl.ac.uk> <87y4j6tgyn.fsf@nicolasgoaziou.fr> <20150626195749.GG5090@fjo-extia-HPdeb> <87zj3iodr4.fsf@ucl.ac.uk> <87egkugfjw.fsf@pierrot.dokosmarshall.org> <878ub1zlzy.fsf@delle7240.chemeng.ucl.ac.uk> <87lhf1i68s.fsf@alphaville.usersys.redhat.com> <87fv581jfv.fsf@ucl.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:55616) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCWS4-0007Zm-Fx for emacs-orgmode@gnu.org; Tue, 07 Jul 2015 13:14:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZCWS0-0003q2-Qo for emacs-orgmode@gnu.org; Tue, 07 Jul 2015 13:14:36 -0400 Received: from linnode.donarmstrong.com ([64.62.190.156]:42307) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCWS0-0003pX-Km for emacs-orgmode@gnu.org; Tue, 07 Jul 2015 13:14:32 -0400 Content-Disposition: inline In-Reply-To: List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: emacs-orgmode@gnu.org On Wed, 01 Jul 2015, Michael Brand wrote: > On Wed, Jul 1, 2015 at 8:27 AM, Eric S Fraga wrote: > > On Tuesday, 30 Jun 2015 at 11:08, Nick Dokos wrote: > >> In what way are you losing information? > > > > Sorry, should have been clear: the time zone information itself. By > > reducing to UTC, you lose one bit of information. Whether that matters > > or not in practice is not clear but I'm always uncomfortable when > > considering data representations that lead to information loss. > > > > I've been trying to come up with an example that would illustrate the > > problem but I've failed so far. > > As an example for the above I suggest to consider a non-stop flight > with a duration of 1:31:00 from Salt Lake City UT to Phoenix AZ, both > cities in different time zones, here intentionally even the same basic > time zone but one with daylight saving and one without. [...] > 2) When the Org file format would support time zones I would use > > * Flight from Salt Lake City UT to Phoenix AZ > <2015-07-01 Wed 10:55 MDT>--<2015-07-01 Wed 11:26 MST> > - *Advantage*: Visibility of the time zones where the event takes > place. Of course, this is even more complicated, as MST could mean UTC+08, UTC-07 or UTC+06:30. That said, lets not make perfect the enemy of the good. I've currently got emacs running under TZ="America/Los_Angeles" even though my machine is in TZ="America/Chicago" precisely because org mode can't yet handle this. I'd be willing to help out as much as I'm able, too. -- Don Armstrong http://www.donarmstrong.com I have no use for "before and after" pictures. I can't remember starting, and I'm never done. -- a softer world #221 http://www.asofterworld.com/index.php?id=221