From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp12.migadu.com ([2001:41d0:2:bcc0::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms5.migadu.com with LMTPS id iAz9GCdixGMEJQEAbAwnHQ (envelope-from ) for ; Sun, 15 Jan 2023 21:29:27 +0100 Received: from aspmx1.migadu.com ([2001:41d0:2:bcc0::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp12.migadu.com with LMTPS id ANbtGCdixGN+XwEAauVa8A (envelope-from ) for ; Sun, 15 Jan 2023 21:29:27 +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 41A22316E7 for ; Sun, 15 Jan 2023 21:29:27 +0100 (CET) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pH9cY-0006x4-2T; Sun, 15 Jan 2023 15:28:50 -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 1pH9cS-0006wa-8E for emacs-orgmode@gnu.org; Sun, 15 Jan 2023 15:28:44 -0500 Received: from stw1.rcdrun.com ([217.170.207.13]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pH9cQ-0001ns-JP for emacs-orgmode@gnu.org; Sun, 15 Jan 2023 15:28:44 -0500 Received: from localhost ([::ffff:197.239.8.177]) (AUTH: PLAIN admin, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 0000000000055DB3.0000000063C461FB.00002AC3; Sun, 15 Jan 2023 13:28:43 -0700 Date: Sun, 15 Jan 2023 23:28:25 +0300 From: Jean Louis To: Max Nikulin Cc: emacs-orgmode@gnu.org Subject: Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Message-ID: Mail-Followup-To: Max Nikulin , emacs-orgmode@gnu.org References: <63c287ca.a70a0220.4bd14.873b@mx.google.com> <87pmbh1hgx.fsf@localhost> <63c2b8e4.a70a0220.e3b6d.0051@mx.google.com> <87edrxyyeq.fsf@localhost> <87bkn1yx59.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.9+54 (af2080d) (2022-11-21) Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-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=1673814567; a=rsa-sha256; cv=none; b=RVQlXVF9oOIBDXe9mj1q/7bFY4gUYNHaOO7vao49qVTozs5W9G5jTa8VmT6Az5TaQvB+Fx pudW4LhF8hIGIdHQSb+5z4A8TNadE/8YqVOFCmrEGcYIe6iNbviDz46ap15oV78GYJ2KTq SCOVxkWFvngp6xkHHz52GXI29pitPKroHC8nJ3o+rt4niOT5+5mHxuluNhT4R21RqVLr0B B3u2E67TiexlCzJNRHS9jABIJ6pv7aaKGXq8bh93g6jFngP+GuiYp0XqBMUC9UiB9N3qjG d3pBIPyQGyiSsXCF8G0Gvn2DYqGYp5rmvLGQOl0ZxtHUdCuz26r7DkQghXJ1HA== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=none; 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=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1673814567; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=bbCCnfEttXa962w05Ezya6YlLdRfgerJTLaKOclt2Pw=; b=A6c99AKxbCvY8jWfuNxWGRWQcEcSgat+Z6C/1Ic1Cwl2BSBtvrwCNncfZTHBMwGubBxweH ROvGuQjTJ94x0yxXpzQS+o9ifSGj542D7NOwN0+VWDunURaVSpkrbnk2AFjYG+plFFJ1j0 2uU8eNSSgbo6y+8TzBsX3QUDQZPL0RNZTn0BuGYoWekfd70Fi542EFlbET83lDZzyErgsr AtENv9hX3B/JsO2rnzMDYdjMvdL9LfhCTDIDC3tUn5KFhhZsd46DOPC43LQwL65mtFjxnU 4tL9gRrtjNscMyprRmCutmpd0u66VIKV4THmcimiRfalQbybM0PQ6Pcz0tZ8HA== X-Migadu-Spam-Score: -2.42 X-Spam-Score: -2.42 X-Migadu-Queue-Id: 41A22316E7 X-Migadu-Scanner: scn1.migadu.com Authentication-Results: aspmx1.migadu.com; dkim=none; 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=none X-TUID: dxVacu9NEYII * Max Nikulin [2023-01-15 08:05]: > I totally agree with the recommendation to use timestamptz for data related > to something in history: billing, bank transactions, etc. > > However it is call to trouble for planned events and schedules. Not > frequent, so almost untested use cases. > > If I remember correctly, another type, timestamp (without tz), may be cast > on demand to any timezone (stored in another column or passed from > application). So it may be used obtain correct UTC timestamp after update of > timezone database. It is about representation. If time is represented as UTC, by user in Brazil, how is somebody in Russia going to understand when is the meeting? Call for trouble is when there is UTC time only as that requires users to calculate themselves the different time zone, instead, computer is for such calculations there. When time is specified with time zone, then user in any ther time zone can see that in his own time zone. In the context of Org files, that would mean that there must exist function which would convert time zone timestamps into local time zone for proper representation. Only with such functions problems are gone. Without such function to convert time zones in different time zone, user will see time zone from Brazil and will run into difficulties. -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns In support of Richard M. Stallman https://stallmansupport.org/