From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp11.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms5.migadu.com with LMTPS id KN4pLyKX2mOlewEAbAwnHQ (envelope-from ) for ; Wed, 01 Feb 2023 17:45:22 +0100 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp11.migadu.com with LMTPS id qLIRLyKX2mN4LwAA9RJhRA (envelope-from ) for ; Wed, 01 Feb 2023 17:45:22 +0100 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 7F544A076 for ; Wed, 1 Feb 2023 17:45:22 +0100 (CET) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pNGDs-0003yK-2h; Wed, 01 Feb 2023 11:44:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pNGDr-0003xk-1H for emacs-orgmode@gnu.org; Wed, 01 Feb 2023 11:44:35 -0500 Received: from mout01.posteo.de ([185.67.36.65]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pNGDo-0006MS-Up for emacs-orgmode@gnu.org; Wed, 01 Feb 2023 11:44:34 -0500 Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id 0EDE324041D for ; Wed, 1 Feb 2023 17:44:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1675269871; bh=jMc9WDD7EMjz/hl3GsC1fQsP3b/0N6Fa/ubX9OqUSI0=; h=From:To:Cc:Subject:Date:From; b=dV8GqdvCQhpul1hqdIufmXPO1Ag4WQ7BQEZrMfXhgCjchqgE32bBpO2iZA88hsM2b SYtiNHaB+eMYYlpyNydGlKB59OKuHjujMIE8yeC4WeanRj/97CCriqffzlFvpvEqNZ MTbFyAFiWEC84pX/kAYaezOcc/XspFVMASATt0Y6TfaV9B8B9IZTHOAF/VP7dUYZSj XsErpwtNrL/hyHtEROzMeRwypz9HwPyxJokyZx1f1xQgmDoCOei2K2IIFENBO/ExBT aaFL5HW5ElLhRyULKCD+Wen4UAqh6rVdNKypCztXNTV1FEnmK/aGUe5v7J3lEUzjkE TGxZ8znDefhZw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4P6SSG0Bq3z6tml; Wed, 1 Feb 2023 17:44:29 +0100 (CET) From: Ihor Radchenko To: Jean Louis Cc: Tim Cross , tomas@tuxteam.de, emacs-orgmode@gnu.org Subject: Re: [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) In-Reply-To: References: <87lelo8c9r.fsf@localhost> <2150768.1675077958@archlinux> <87tu063ox2.fsf@localhost> <87h6w63jgg.fsf@localhost> <86wn51g661.fsf@gmail.com> <87357pn57t.fsf@localhost> <86sffpg1bv.fsf@gmail.com> Date: Wed, 01 Feb 2023 16:45:07 +0000 Message-ID: <87wn51ibcc.fsf@localhost> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=185.67.36.65; envelope-from=yantar92@posteo.net; helo=mout01.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-orgmode@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-orgmode-bounces+larch=yhetil.org@gnu.org Sender: emacs-orgmode-bounces+larch=yhetil.org@gnu.org X-Migadu-Country: US X-Migadu-Flow: FLOW_IN ARC-Seal: i=1; s=key1; d=yhetil.org; t=1675269922; a=rsa-sha256; cv=none; b=AC8tbwPshr1KvrNiisp96x5kcnMjN1S8mAOAmnYuKtTceAwnuzNQdt8/nL27xvgBYWanV9 PDqv8PUxQpsmXrLx8wd51IJA6StCoRN+/twZcaHwWdlQDGBl4wao/Lg/beIpAn61gm8LLP SEMTuZ7S7mK9TxZQZFJe6NGs45t8tqmShpyT/2SqqyaG5np0y3OHBeP4UzgnyOdQ2Y03jQ Qzcbd0mq7S4XUOgq9cldISBRf7j4c4xtHF6syLfjUplICkLprWbyDUdAGrzlOKKD/7A4mp INwGdq73YOJZ6NhyOS5OlHzwgRQKnBPGgNWBSr/ceN6oaEJhC3TQA7d5fmsfQg== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=pass header.d=posteo.net header.s=2017 header.b=dV8GqdvC; spf=pass (aspmx1.migadu.com: domain of "emacs-orgmode-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="emacs-orgmode-bounces+larch=yhetil.org@gnu.org"; dmarc=pass (policy=none) header.from=posteo.net ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1675269922; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post:dkim-signature; bh=vhv6I7Y4PNOlBvnMhJ4YZ/mcMgVEnFmFuAseqfrCtao=; b=ihJPjaQqxBBaA/QwijXlE+j62ASpdKdcozqmW5asV4xNd2ju1uXRZdKy/VxfvqGAo9GgjH efTs60WRqgxq38htKVUNX4ekVcDz4K5ZiNg4aqlHhZcAorMxwKqWVCwbknVbksBhIhTES3 FHz8wWqFhs8dvIcfWA6sWnFsU8JjBu5/zaNFwLFPHzFr052Hu+nXTyWaez76ZInVGlaJEq U+RlQgooXAZs1uvaWQ2x3Xhyoc5o2YKEsiaPXTncdjPk20zfIdZTaHbNZYZsGS8a1wJOVk ATQOgG9DWjTLtCt+3C/JAK1VXNkl38oWfKXWzlxqpxAYjixt1n4iaGuVj+fcSQ== Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=posteo.net header.s=2017 header.b=dV8GqdvC; spf=pass (aspmx1.migadu.com: domain of "emacs-orgmode-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="emacs-orgmode-bounces+larch=yhetil.org@gnu.org"; dmarc=pass (policy=none) header.from=posteo.net X-Migadu-Scanner: scn1.migadu.com X-Migadu-Spam-Score: -4.54 X-Spam-Score: -4.54 X-Migadu-Queue-Id: 7F544A076 X-TUID: Sy0CxizEB3+e Jean Louis writes: >> The problems of daylight savings transition points is fairly well >> understood and I think it is fairly well accepted that there is >> ambiguity arising from the use of daylight savings. > > The only ambiguity is if you miss to understand that "time zone" > definition already contains specification of daylight savings. > > If you do understand it, then there will be no ambiguity at all. You are incorrect here. In such scenarios, time zone name must also be accompanied by DST flag. Just supplying the time zone is not enough. Note how `encode-time' TIME argument has both DST flag and the time zone name: (SECOND MINUTE HOUR DAY MONTH YEAR IGNORED DST ZONE) DST is necessary exactly in the ambiguous situations like I described, when we must know if day saving time is in effect or not __in addition__ to time zone name. -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at