From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Abrahamsen Subject: Re: Timezones revisited Date: Wed, 01 Feb 2017 09:33:47 -0800 Message-ID: <8737fx4xz8.fsf@pellet> References: <20170131230346.GV7187@volibear.adamsinfoserv.com> <87shnxuczj.fsf@pellet> <20170201162016.GJ7187@volibear.adamsinfoserv.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:43695) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cYynE-0008Tj-1r for emacs-orgmode@gnu.org; Wed, 01 Feb 2017 12:34:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cYynA-0003Mx-VN for emacs-orgmode@gnu.org; Wed, 01 Feb 2017 12:34:04 -0500 Received: from [195.159.176.226] (port=41095 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cYynA-0003Mo-PD for emacs-orgmode@gnu.org; Wed, 01 Feb 2017 12:34:00 -0500 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1cYyn2-00020s-SZ for emacs-orgmode@gnu.org; Wed, 01 Feb 2017 18:33:52 +0100 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" To: emacs-orgmode@gnu.org Russell Adams writes: > On Wed, Feb 01, 2017 at 11:14:15AM -0500, Peter Neilson wrote: >> On Wed, 01 Feb 2017 10:50:24 -0500, Eric Abrahamsen >> Presumably everyone already knows that the timezones are more complicated >> than hoi polloi believe? The offsets are not always integer values of >> hours. For example, Newfoundland time is UTC−03:30. Additional >> complications include daylight saving time and the many historical >> versions of timezones. The definition of UTC can remain pretty much >> constant, but local-timezone time varies as a function of both location >> and calendar date. > > Emacs has a timezone conversion function, which I assume pulls from > the tz info database like all the other system commands. > > Local time zone should be the system time zone or one defined as a > per-buffer variable. Right, we'd be doing all our calculations based on the car of `current-time-zone' (or the converted equivalent). I think that would get us as close to "correct" as possible, and necessary. Eric