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 OE+PB4MW1mMA5gAAbAwnHQ (envelope-from ) for ; Sun, 29 Jan 2023 07:47:31 +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 qFbDBoMW1mP6DQAAauVa8A (envelope-from ) for ; Sun, 29 Jan 2023 07:47:31 +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 A7587157BB for ; Sun, 29 Jan 2023 07:47:30 +0100 (CET) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pM1SK-0008En-Js; Sun, 29 Jan 2023 01:46:25 -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 1pM1SI-0008Eb-CX for emacs-orgmode@gnu.org; Sun, 29 Jan 2023 01:46:23 -0500 Received: from mail-wr1-x435.google.com ([2a00:1450:4864:20::435]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pM1SF-0000kl-Jl for emacs-orgmode@gnu.org; Sun, 29 Jan 2023 01:46:21 -0500 Received: by mail-wr1-x435.google.com with SMTP id b7so8410665wrt.3 for ; Sat, 28 Jan 2023 22:46:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wakatara.com; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=ZK7ep0k8/NwXPs65USh4YQ09u48CDolU7QSzg8ClxOo=; b=X/zkF4fB4mvHqhu+NOABcNc/dw1hj7Gzl/8UPXpGHGW/34bOA045A3QgAoO7GX13MU Z+gL+rnvz/xsgj1CTSl1udxOXscuMZOhHH7uJGDbfXwb2op8klI1G11VTjZiTW9OsNrn MxlpdUUvq3rPA6+yw4/EbsnZAOVFzkvobtkhjMWYHDcWweeTbqAvKyZHI4XifcRFb/5s 0+FsNLfknVragTx6Y6jeX1TJCCIzFdd0RJ4en+nUp2sY3Pcuu8z0Kl3NXaxM0GYznavc XzYkU6AvTKvND6MPDWxpPeigujuGfuCLENTkT5WPeZ9G17fKOv9kMsB53pSc0EUxlqLl 4v3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=ZK7ep0k8/NwXPs65USh4YQ09u48CDolU7QSzg8ClxOo=; b=i8DkpJ3BolCceldYrQPHRl70gDov9+/zWdP73mK0NLINwPocXxAay2EKG9hMn08qFI pqfAKuKpmt6mAJbmQ5MRZHFe8c8l63/5fG2wQIFT//YoiyNwJ0cqtq30AlHPB3WdTj9G MU32xc3kB3hASMmP6/s5SBb1QBzjlHFr+2MR4P/6j9VHySHvy7Hvso5FhF5NO4+q9hVc xd86fpnc4lKTztTBukNab9qkWtZJouuU8woVh74lz2CtLpOebqiC7IltHCQ6FXkZQfj+ PpvV7o5rw342kwfO96Ig/qUsfPUOU+soLqTyJv8M/tnVqIURKRzuovKXe3/6ydtp9m2F JJaQ== X-Gm-Message-State: AO0yUKXqho/MCp0rd+HEeBfzoE+8ueXDJYGcnkAYkFnvZdyOQUCPxbjX jHe10HEyLT/e2jDQ0lpoTFwRs8mCPGQ3w2lnGvtkWA== X-Google-Smtp-Source: AK7set/VOGNbiK8MaDgY7e6gPSAVQVVAFhULNqSVcgZoUj/ZHaCkGe7u+ieHRsrboZ/dTLDQgsvItVEOmCCOiJs2RMg= X-Received: by 2002:a5d:5088:0:b0:2bf:e929:1af4 with SMTP id a8-20020a5d5088000000b002bfe9291af4mr38880wrt.18.1674974776768; Sat, 28 Jan 2023 22:46:16 -0800 (PST) MIME-Version: 1.0 References: <63c9b654.170a0220.d82d2.4254@mx.google.com> <87mt6e86sr.fsf@tsdye.online> <63c9d976.620a0220.a7d40.113b@mx.google.com> <87tu0mjb24.fsf@tsdye.online> <63ca1283.170a0220.5bc81.0fdd@mx.google.com> <87pmb9k8oi.fsf@tsdye.online> <3035CDD5-41DD-4516-9E4E-9E0DF16BE2E0@gmail.com> <63d43ec5.630a0220.87fac.44e2@mx.google.com> <871qnd979o.fsf@tsdye.online> In-Reply-To: <871qnd979o.fsf@tsdye.online> From: Daryl Manning Date: Sun, 29 Jan 2023 13:46:05 +0700 Message-ID: Subject: Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda To: "Thomas S. Dye" Cc: emacs-orgmode@gnu.org Content-Type: multipart/alternative; boundary="00000000000093d10305f36174d0" Received-SPF: pass client-ip=2a00:1450:4864:20::435; envelope-from=daryl@wakatara.com; helo=mail-wr1-x435.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_PDS_OTHER_BAD_TLD=0.01 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-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1674974850; 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=ZK7ep0k8/NwXPs65USh4YQ09u48CDolU7QSzg8ClxOo=; b=Urp39jYTzWGyO9hXUehk0geMZN2qZqXx8bXlPzWo/vQQWbNEV81S5etIG3Rp+zwJH5KqDg SvOV1QVdgacqLpG7h61heI/oKraUb2GbZfTiUe2UCPBI+AH+NX6zbrY18eokp8vNA7lbnQ 8YgHlR7bKzpMEbQhidcqOSlQEnG0ns92IiURUrnVBbV7Sah8VpP2C/XAoMiPqIqn1DScYv zsKbKpqZneqSY6Pxyh0F+JCww+JwzKDWw745Ia4Jz6Ah6r7FdzZ3R6/2Cym/V+50+TmBsh bEUPyRQxP2FDyy+OUebZvudYHN6SKd+u6j9pec9cOdpI7ywa9JCiirUEspc/rQ== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=pass header.d=wakatara.com header.s=google header.b="X/zkF4fB"; dmarc=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-Seal: i=1; s=key1; d=yhetil.org; t=1674974850; a=rsa-sha256; cv=none; b=ogKpQM1uMKkvojBcwSplFrwBOJWpWjgjyGBnvDyKdl8byB6PcfiiChZ+HRsrKRs6gZk4ON AfUE/WJo26fB+9KMF0KYQhtDPgRj8eEBu1dwA/9UBjHzQNNNaeKj/eRxOT510zOpmOQuui p8AntYkd4nahpr1+8CoTBKw66KjhqkC33UNaOfwwPKaGpygV2cD+0/HW6EmuEA5RQLad9E yuY8ZIEtxg4gGKKh2N9GtZMqpz442BVds72Qw+1sc4Hgb3O4GPbpQZCxw0wsnBddM1nVzH UbpVT/EylWr8PAeKBSnVhLmn3p//pDv6vWXJUq+JGRFMo4tHfU1+xSey1/B/oQ== X-Spam-Score: -5.53 X-Migadu-Spam-Score: -5.53 Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=wakatara.com header.s=google header.b="X/zkF4fB"; dmarc=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-Queue-Id: A7587157BB X-Migadu-Scanner: scn1.migadu.com X-TUID: vQBnTJf56Bz7 --00000000000093d10305f36174d0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable All these discussions are really great, devil is in the details and all, but is anyone working on implementation code for this? It=E2=80=99s tricky = to have visibility on WIP on org-mode - probs just me not knowing where to look tbh (but big believer that working code is progress=E2=80=A6 =F0=9F=98=8A) Daryl. On Sun, 29 Jan 2023 at 13:36, Thomas S. Dye wrote: > > Jean Louis writes: > > > Time offset does not independently exists without time zone. > > While you > > represent it without time zone, you have to observe time zone > > first, > > before deriving time offset from it. > > > > UTC offset exists without time zone. UTC is absolute time and > offsets from it do not refer to political time in a time zone. > They refer to local *solar time* at a particular place. > > > Read from: > > https://en.wikipedia.org/wiki/UTC_offset > > > > ,---- > > | Daylight saving time > > | > > | Several regions of the world use daylight saving time (DST) > > and the > > | UTC offset during this season is typically obtained by adding > > one hour > > | to local standard time. Central European Time UTC+01:00 is > > replaced by > > | Central European Summer Time UTC+02:00, and Pacific Standard > > Time > > | UTC=E2=88=9208:00 is replaced by Pacific Daylight Time UTC=E2=88=9207= :00. > > `---- > > Your wikipedia citation puts it like this: "The UTC offset (or > time offset) is an amount of time subtracted from or added to > Coordinated Universal Time (UTC) time to specify the local solar > time (which may not be the current civil time, whether it is > standard time or daylight saving time)." > > Note that the quote distinguishes UTC offset from standard time > and daylight saving time, which refer to time zones. > > This distinction between absolute time (solar time) and space/time > (time zone) is fundamental. Confusing them leads to no good. > > hth, > Tom > > -- > Thomas S. Dye > https://tsdye.online/tsdye > --00000000000093d10305f36174d0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
All these discussions are really great, devil is in the d= etails and all, but is anyone working on implementation code for this? It= =E2=80=99s tricky to have visibility on WIP on org-mode - probs just me not= knowing where to look tbh (but big believer that working code is progress= =E2=80=A6 =F0=9F=98=8A)

= Daryl.

On Sun, 29 Jan 2023 at 13:36, Thomas S. Dye <tsd@tsdye.online= > wrote:

Jean Louis <bugs@gnu.support> writes:

> Time offset does not independently exists without time zone.
> While you
> represent it without time zone, you have to observe time zone
> first,
> before deriving time offset from it.
>

UTC offset exists without time zone.=C2=A0 UTC is absolute time and
offsets from it do not refer to political time in a time zone.
They refer to local *solar time* at a particular place.=C2=A0

> Read from:
> https://en.wikipedia.org/wiki/UTC_offset
>
> ,----
> | Daylight saving time
> |
> | Several regions of the world use daylight saving time (DST)
> and the
> | UTC offset during this season is typically obtained by adding
> one hour
> | to local standard time. Central European Time UTC+01:00 is
> replaced by
> | Central European Summer Time UTC+02:00, and Pacific Standard
> Time
> | UTC=E2=88=9208:00 is replaced by Pacific Daylight Time UTC=E2=88=920= 7:00.
> `----

Your wikipedia citation puts it like this: "The UTC offset (or
time offset) is an amount of time subtracted from or added to
Coordinated Universal Time (UTC) time to specify the local solar
time (which may not be the current civil time, whether it is
standard time or daylight saving time)."

Note that the quote distinguishes UTC offset from standard time
and daylight saving time, which refer to time zones.

This distinction between absolute time (solar time) and space/time
(time zone) is fundamental. Confusing them leads to no good.

hth,
Tom

--
Thomas S. Dye
https://tsdye.online/tsdye
--00000000000093d10305f36174d0--