From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp2 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id MDX2OkHO1l+kWgAA0tVLHw (envelope-from ) for ; Mon, 14 Dec 2020 02:30:25 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp2 with LMTPS id wAO/NkHO1l/GQAAAB5/wlQ (envelope-from ) for ; Mon, 14 Dec 2020 02:30:25 +0000 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 030A2940367 for ; Mon, 14 Dec 2020 02:30:24 +0000 (UTC) Received: from localhost ([::1]:58844 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kodcx-0002Dy-Mo for larch@yhetil.org; Sun, 13 Dec 2020 21:30:21 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50406) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kodcS-0002Ds-Ed for emacs-orgmode@gnu.org; Sun, 13 Dec 2020 21:29:48 -0500 Received: from mail-wm1-x329.google.com ([2a00:1450:4864:20::329]:39256) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kodcQ-0000hC-Li for emacs-orgmode@gnu.org; Sun, 13 Dec 2020 21:29:48 -0500 Received: by mail-wm1-x329.google.com with SMTP id 3so13863043wmg.4 for ; Sun, 13 Dec 2020 18:29:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=XrnwHnHqUzNbTOkkE/55d8WmF37+rQ8qEsZ490R2Dok=; b=OvXEU+ssjUFu6UWoprl+GFKNJV8VlBKzh2/ZKocmKJ6TwCGIlkPHHu07VBOjsc6emD PZhhjwa7Fum27fjyTOeB87oQZ0db8zt2peR0AmATD+zGjMAB/togy0kQ+fd79zwJVOlT MnPqpUPtRmqPNhvuNjlabHm+ohwfUnbdSrg8MBxUmFRynU2uCm3rG5JgRZ6QvpZXDS2I CkY7D12L6BNLu/P6dSTC/umXkJU08yl0ALowbzGGR3gptanOH8fR88m9KYG5QT7KOCU+ lpbsV8IP2fPta7pdcE3t/5vZO06Z1WFptGNKHDqSepARR+IujcsBnz3onz2e+EbMAc8T 2/Uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=XrnwHnHqUzNbTOkkE/55d8WmF37+rQ8qEsZ490R2Dok=; b=eeOU4yvDnQH/8qJkE8XwoUNKRfE2heMSb5yZSYn13Dm0iORySl1ibjZBhKn+W29rVt SG9OuwOj8sQwUEkGp08B3ppo1wgvt/3MvSV7QJ4QLiOLW9Ka3IpuC1gNexFqt9s/YINK KMeT2y2gaYV5R+dyQnwBn22/E1xjOHytQ3S4Cqe4DLRrXmjZ38XXry+MzNNIGxfPqblu gjy5s7YPOtaj2qmi6pK3X30WSjzEGb8guQoDZjlZTuej41kOk+MYFcz/WIn9qmt8Xz9R smUyeC0ihvnjVBw0gEaG1eZucbtg6dS0KlX0Mtk42viptuv1dL7RE8ekt6WQhHb8Krae h6eQ== X-Gm-Message-State: AOAM530NYr+1aNCyIe7zkkS8ZJ/qAk0Mvw90mWT8Usv8e31054pG6LUX qopwSS9RkgIr+XNFZrMP+fZIilmGpUX7XjI29ok= X-Google-Smtp-Source: ABdhPJxAbAjpqGXTh2YWH0kWrkAQ6bvzpd56k3bDbnPfSg0zp1CGUtBBzwV8K8ynFb78nbaolf0+VV0s/QAVcu1hMEg= X-Received: by 2002:a1c:35c2:: with SMTP id c185mr25760012wma.74.1607912984949; Sun, 13 Dec 2020 18:29:44 -0800 (PST) MIME-Version: 1.0 References: <87wnxrjjl2.fsf@gmail.com> <87lfe5ju0t.fsf@gmail.com> <871rfuvdh9.fsf@gmail.com> In-Reply-To: From: "Alan E. Davis" Date: Sun, 13 Dec 2020 18:29:01 -0800 Message-ID: Subject: Re: org-table change time from UTC to other timezones To: Maxim Nikulin Content-Type: multipart/alternative; boundary="0000000000004c365905b6636a39" Received-SPF: pass client-ip=2a00:1450:4864:20::329; envelope-from=lngndvs@gmail.com; helo=mail-wm1-x329.google.com X-Spam_score_int: 4 X-Spam_score: 0.4 X-Spam_bar: / X-Spam_report: (0.4 / 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, FREEMAIL_FROM=0.001, FROM_LOCAL_NOVOWEL=0.5, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URI_DOTEDU=1.999 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-orgmode@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: org-mode Errors-To: emacs-orgmode-bounces+larch=yhetil.org@gnu.org Sender: "Emacs-orgmode" X-Migadu-Flow: FLOW_IN X-Migadu-Spam-Score: -3.00 Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=OvXEU+ss; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (aspmx1.migadu.com: domain of emacs-orgmode-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=emacs-orgmode-bounces@gnu.org X-Migadu-Queue-Id: 030A2940367 X-Spam-Score: -3.00 X-Migadu-Scanner: scn1.migadu.com X-TUID: 8/ogG/ybhjFg --0000000000004c365905b6636a39 Content-Type: text/plain; charset="UTF-8" Maxim: Both of these links, like your comments, are incredibly useful. Happy New Year (however you may measure that thing) On Sun, Dec 13, 2020 at 9:05 AM Maxim Nikulin wrote: > 2020-12-13 Alan E. Davis wrote: > > > > I think R would not be too unwieldy as a hammer here. My use case is a > > humble one: just take a several clock times in HH:MM format (utc) and > > adjust to another timezone by adding or subtracting the relevant number > > of hours. The day of week is not important; i will have to deal with > > it. I did imagine a conditional subtraction by adding of subtracting > > 24:00 as needed. > > Likely your approach is suitable for you and you could ignore my > comments. I just live in a city having longitude that should be (and it > was) the border between time zones, so majority do not like any > decision. Since cancellation of DST 10 years ago, local time has been > shifted 2 times... > > To get time offset for some timezone, it is necessary to specify > timestamp, so a date is required in addition to time. Namely day of week > is mostly irrelevant. > > Time transitions are usually arranged at night when most of people are > not active. Astronomers is a different case, that is why their chance to > face a timezone bug is higher. > > When operations with arbitrary time zones are not required and a process > could be run with TZ variable set to desired time zone, libc functions > should work correctly. I have not tried elisp functions > > https://www.gnu.org/software/emacs/manual/html_node/elisp/Time-Zone-Rules.html > > A bookmark for those who still hopes to avoid complications with > time-related operations > > Falsehoods programmers believe about time > > https://infiniteundo.com/post/25326999628/falsehoods-programmers-believe-about-time > > > -- "This ignorance about the limits of the earth's ability to absorb pollutants should be reason enough for caution in the release of polluting substances." ---Meadows et al. 1972. Limits to Growth . (p. 81) --0000000000004c365905b6636a39 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Maxim:

Both of these links, = like your comments, are incredibly useful.=C2=A0=C2=A0

<= /div>
Happy New Year (however you may measure that thing)

On S= un, Dec 13, 2020 at 9:05 AM Maxim Nikulin <manikulin@gmail.com> wrote:
2020-12-13 Alan E. Davis wrote:
>
> I think R would not be too unwieldy as a hammer here.=C2=A0 My use cas= e=C2=A0 is a
> humble one: just take a several clock times in HH:MM format (utc) and =
> adjust to=C2=A0=C2=A0another timezone by adding or subtracting the rel= evant number
> of hours.=C2=A0 The day of week is not important; i will have to deal = with
> it.=C2=A0 I did imagine a conditional subtraction by adding of subtrac= ting
> 24:00 as needed.

Likely your approach is suitable for you and you could ignore my
comments. I just live in a city having longitude that should be (and it was) the border between time zones, so majority do not like any
decision. Since cancellation of DST 10 years ago, local time has been
shifted 2 times...

To get time offset for some timezone, it is necessary to specify
timestamp, so a date is required in addition to time. Namely day of week is mostly irrelevant.

Time transitions are usually arranged at night when most of people are
not active. Astronomers is a different case, that is why their chance to face a timezone bug is higher.

When operations with arbitrary time zones are not required and a process could be run with TZ variable set to desired time zone, libc functions
should work correctly. I have not tried elisp functions
https://www.gnu.org/so= ftware/emacs/manual/html_node/elisp/Time-Zone-Rules.html

A bookmark for those who still hopes to avoid complications with
time-related operations

Falsehoods programmers believe about time
https://infiniteu= ndo.com/post/25326999628/falsehoods-programmers-believe-about-time




--
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 &qu= ot;This ignorance about the limits of the earth's ability to absorb
= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pollutants should be reason enough for= caution in the release
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 of pollutin= g substances."
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0=C2=A0 ---Meadows et al.=C2=A0=C2=A0= 1972.=C2=A0 Limits to Growth. =C2=A0=C2=A0 =C2=A0 (p. 81)=C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0
=
--0000000000004c365905b6636a39--