From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp11.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 UDnyGluYwmNzDQEAbAwnHQ (envelope-from ) for ; Sat, 14 Jan 2023 12:56:11 +0100 Received: from aspmx1.migadu.com ([2001:41d0:8:6d80::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp11.migadu.com with LMTPS id yJb0GluYwmO5HQEA9RJhRA (envelope-from ) for ; Sat, 14 Jan 2023 12:56:11 +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 0B44F25C68 for ; Sat, 14 Jan 2023 12:56:10 +0100 (CET) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pGf8A-0007W8-Uh; Sat, 14 Jan 2023 06:55:26 -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 1pGf89-0007Vj-Kc for emacs-orgmode@gnu.org; Sat, 14 Jan 2023 06:55:25 -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 1pGf88-0002Cc-BI for emacs-orgmode@gnu.org; Sat, 14 Jan 2023 06:55:25 -0500 Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pGf84-0005nI-FA for emacs-orgmode@gnu.org; Sat, 14 Jan 2023 12:55:20 +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: Sat, 14 Jan 2023 18:55:14 +0700 Message-ID: References: <63c287ca.a70a0220.4bd14.873b@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: <63c287ca.a70a0220.4bd14.873b@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=0.092, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, NICE_REPLY_A=-0.001, 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-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=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=gmail.com (policy=none) ARC-Seal: i=1; s=key1; d=yhetil.org; t=1673697371; a=rsa-sha256; cv=none; b=SFiA+efRGzgtK0DrinsR15ixxJtKpctrIKi2sOe3NdVku2PoMDlJsAD1KRQcwOR0C22yRV ckPUDZXXWq9RhHZEa01OZ0nXcfmdcjzke4mStgiDVT3yh9FqBV2E249QVqRGV1UFIpBB/B f2mQhk/dMiMT0w2CRycaQyCo3j7TALK33eEAdVi2xWOnvd2FHsHG2qOEliI1Q/reCuZArq xH7fKV428w11LJRvEBmGBVTfL4ObkUtGkI7/qpsRL2Tk6w0c3q4uJkBKt6EySSRKx+iMtR GA48ZwLy8ADbLSMBII22DeT4GeAnS4XhFIGper8MTHz6Ooy4dSpctFk5K5LNVw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1673697371; 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=VnRzCvn9goxcT7FG4BlLrw23MTgTSehUlDcUIklZ/rU=; b=aOomyg+jzl4Itwyg7N057lrA8YEMeLnDZa4AQiMZSJqT7Q4etGl8c4ySTVI42kMcaUYKND GIUgoqvgQennZmTGOwBpLDxyMNR2mPuZqY2crOLUkxnIEV8US4y2xzPiUHZPtrH1Rx1O6b oaMg37luzbVr0QM9BnYc/nhk0FxyD6sB5w6DWi7F587xGkKgQiooZ/qIHR/B/xXJGhJYOD bpkJ1sHOmdOCLM+XhDO7TxWdaV60f0fWXv0bRwJt/Vr2fB3cN0EhYArPwAMEU6cEGwWZWI JvwaI/EmULRCmF71U5SN8HDUw1U37qTHdESWywKWQVFiiTV23y6MGkexu18t0w== X-Migadu-Queue-Id: 0B44F25C68 X-Migadu-Scanner: scn0.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=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=gmail.com (policy=none) X-Migadu-Spam-Score: -2.81 X-Spam-Score: -2.81 X-TUID: 1oilCA9XI8D+ On 14/01/2023 16:32, Tim Cross wrote: > > If org was to add TZ capabilities to timestamps, the underlying format > would have to be UTC. ... > can change based on various criteria, including political whims > (e.g. Australia eastern DST transition date was changed in 2000 because > Sydney hosted the Olympics that year). Due to this particular reason storage format for significant fraction of future timestamps (but not always) must not be in UTC 2024-01-14 Sun 21:14:58 ACS (+0930, Australia/Darwin) is not the same as 2024-01-14 Sun 11:45:58 UTC (+0000, Z) despite currently it is. Depending on use case the same particular fields of timestamp may be authoritative or derived for user convenience from other data. UNIX timestamps in seconds in UTC timezone almost unavoidable will be used underneath, but operations like "start of next day" require non-trivial computations to find if time zone offset changes in between.