From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp12.migadu.com ([2001:41d0:8:6d80::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms5.migadu.com with LMTPS id CNNwCd4SymPfMwAAbAwnHQ (envelope-from ) for ; Fri, 20 Jan 2023 05:04:46 +0100 Received: from aspmx1.migadu.com ([2001:41d0:8:6d80::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp12.migadu.com with LMTPS id OG1WCd4SymNKJAAAauVa8A (envelope-from ) for ; Fri, 20 Jan 2023 05:04:46 +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 B5E5E3B38F for ; Fri, 20 Jan 2023 05:04:45 +0100 (CET) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pIidI-00038U-BQ; Thu, 19 Jan 2023 23:04:04 -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 1pIidG-00037c-4D for emacs-orgmode@gnu.org; Thu, 19 Jan 2023 23:04:02 -0500 Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pIidE-0006yq-GZ for emacs-orgmode@gnu.org; Thu, 19 Jan 2023 23:04:01 -0500 Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pIidB-0009GU-Su for emacs-orgmode@gnu.org; Fri, 20 Jan 2023 05:03:57 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: emacs-orgmode@gnu.org From: Max Nikulin Subject: Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Date: Fri, 20 Jan 2023 11:03:51 +0700 Message-ID: References: <63c66048.630a0220.427bf.a5f6@mx.google.com> <87r0vtiks0.fsf@localhost> <63c671c0.a70a0220.61aa5.56b8@mx.google.com> <87fsc88aq9.fsf@localhost> <63c7dd3d.170a0220.6b4d6.f84f@mx.google.com> <877cxk6oeu.fsf@localhost> <63c86454.170a0220.80970.652d@mx.google.com> <63c8f5a6.170a0220.ea8cf.7f96@mx.google.com> <63c9b654.170a0220.d82d2.4254@mx.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Content-Language: en-US In-Reply-To: <63c9b654.170a0220.d82d2.4254@mx.google.com> Received-SPF: pass client-ip=116.202.254.214; envelope-from=geo-emacs-orgmode@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: 27 X-Spam_score: 2.7 X-Spam_bar: ++ X-Spam_report: (2.7 / 5.0 requ) BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FORGED_GMAIL_RCVD=1, FORGED_MUA_MOZILLA=2.309, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, NICE_REPLY_A=-0.094, NML_ADSP_CUSTOM_MED=0.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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=1674187485; a=rsa-sha256; cv=none; b=dViXzBVvLq3GPa2whwrUWEXbP+stUrGn7qL8R7Z8/d/geTZCu/Ox3lDNDO2iuJF8dyOzVg LIQoInVH4/K+lqdqt1lpARnTkS7CMMMIDRtqK7zPr8SlyeaQnLmCROZGqcjLtzQLGu0WtS j+9gbuSeT68XrFfRgmaOOEzBrpYV/wK04jqfNMieCPky5Vo3XDJgxTtl/LvPnHj1ysREnP L7s6ijDpG9ciS7SojEPP8w8GSyPc06/92EVCZIc4n/Grhqc1F96ERMb4PDLR7gV+mxPOtd tUs7nkWRszdW9XiH1shO3VhWRvbI76wHb7pUjtHttI37/XtCRCmQRuLhlYQSVw== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=gmail.com (policy=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" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1674187485; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to: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=eTee+Jvbcrp8mM4/vqigurRqbzyy39pDDlq92+PoTKQ=; b=bxIMOTkgUs8zkFxfdhvOsAZeQhSfeFo8zW1H+H91dkwe4TCu+imW0veekVKHbVBJRk9Y3D btAOphTDPEkAxqoPbk+GzmEF7MdfJlAgnO3EkM1GF1zG3Ien4qRu12Cpa++7YEZ/REBUhf 5kDtaF2d1ynlnDjMlSIsYOcq6bR5N9Rr55WwuT/rejaXTcQkBqt9Z4lr10S7qcD1+01Cep sAU6mFXPbMBMNLdhOSMkcOs2nJVNt7WP9GuSQWeiP4OPRd2dv65k3Uo1J9slHcjZKVwN6X nBKsWQKkboiQpGlAwB3tLnlq8tnNHVmF/o4Jo92shBuAYIe4oGPqFFVTxrOEQA== X-Spam-Score: 3.79 X-Migadu-Queue-Id: B5E5E3B38F Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=gmail.com (policy=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" X-Migadu-Scanner: scn0.migadu.com X-Migadu-Spam-Score: 3.79 X-TUID: jwNQL0Dyf64r On 20/01/2023 03:09, Tim Cross wrote: > To reiterate for the last time, there are 2 clear and different use > cases for timestamps associated with meetings. > > 1. A meeting timestamp for a meeting where all the participants are in > the same time zone. ...> 2. A meeting timestamp for a meeting where all the participants are in > different time zones.... Tim, every scheduled meeting event is associated with some particular time zone, often implicitly. So it is single use case. It is up to participants to negotiate which timezone is the primary one for each event. It is matter of people communication, not technical issue. First Monday 15:00 is (almost) equally precise for - Australia/Canberra having DST - Australia/Darwin where currently no DST - +1000 (the highest chance of improper use unfortunately) - UTC Aside from time transition intervals, it is possible to take any of this variant and to present time local for other participant across the globe. Storage timezone may differ from the current user preference which time zone should be used to display timestamp or to export it. The problem arises when several participants believe that their timezones are primary ones and they do not sync their schedules through a shared file or a DB entry. An application can not solve this problem, but it might try to help to identify it. Some efforts are necessary from user side. Timestamp should contain list of timezones of other participants and cached local time. In such case an application may warn users that local time values become inconsistent due to DST transitions or due to update of time zone database. Unsure to what degree it should be implemented in Org. So - It is participants fault if a meeting is not associated with particular timezone - Having a fair time handling library, it does not matter what time zone is used to schedule the meeting.