From: "Thomas S. Dye" <tsd@tsdye.online>
To: Max Nikulin <manikulin@gmail.com>
Cc: emacs-orgmode@gnu.org
Subject: Re: UTC or not UTC for timestamps in the past ([FEATURE REQUEST] Timezone support in org-mode)
Date: Sat, 21 Jan 2023 20:17:14 -1000 [thread overview]
Message-ID: <87r0vnhxj6.fsf@tsdye.online> (raw)
In-Reply-To: <tqiirj$7td$1@ciao.gmane.io>
Aloha Max,
Max Nikulin <manikulin@gmail.com> writes:
> Let's consider the following timestamp
>
> [2023-01-22 Sun 08:29@+1100]
>
> "@" is unimportant here, I take it from Ihor's examples. This
> timestamp is from
> the "Date:" header of your message. It is not UTC, but in my
> opinion it is
> equally precise (disregarding seconds) to a UTC timestamp.
>
> Would you prefer to have timestamps in your files in such form
> or as
>
> [2023-01-21 Sat 21:29Z] ([2023-01-21 Sat 21:29@UTC], [2023-01-21
> Sat
> 21:29@+00:00], etc)?
>
> Maybe [@1674336588] (seconds since epoch)?
>
> I consider storage format as a part of Org UI, so I believe that
> [2023-01-22 Sun
> 08:29@+1100] with offset of the usual time zone is more
> convenient than
> [2023-01-21 Sat 21:29@+0000]. Overlays may present your local
> time in both
> cases, but raw value with usual offset is easier to comprehend.
>
> When a file is shared by a group of people spread across the
> globe, they are
> free to use UTC or another fixed timezone or do not care at all
> concerning
> particular offset, it just should present.
UTC is not a timezone. It is absolute time.
> Postgres has a reason to insist on UTC since timestamps are
> stored in binary
> format as microseconds since epoch. It is important for
> performance and there is
> no room to specify offset. Org has to parse timestamps from
> strings anyway, so
> it is better to use format more convenient for humans.
Agreed.
> A side note. In my opinion, *by default* timestamps should be
> created in local
> time with no offset or timezone. There are should be some
> preferences to enable
> absolute timestamps and a function to fix offsets or timezone
> identifiers for
> existing timestamp when the user realizes that they become
> necessary (e.g.
> before a trip).
I don't think there should be a default. If I'm correct that
occurrences, events relative to user, and events not relative to
user exhaustively classify the possibilities, then Org should
insist that timestamps conform to one of these three
possibilities. If the classification is complete, then there is
no need for a catch-all default.
> So I do not see any advantages of UTC in comparison to time
> offset specific to
> particular time zone, usually user's local one. My vote is
> [2023-01-22 Sun
> 08:29@+1100] and not [2023-01-21 Sat 21:29@UTC] (of course, only
> in cases when
> identifiers like Australia/Sydney do not matter) with a
> configuration option
> with timezone used fix offsets in stored timestamps.
The disadvantage of time offset specific to a particular timezone
is that the timezone offset wrt UTC can change arbitrarily. This
is a potential problem if the arbitrary change takes place between
the creation of the timestamp and the happening it identifies. In
contrast, UTC is guaranteed not to change. It is not a timezone,
it is absolute time, a pure continuum. It is a requirement of
occurrences.
I'm not sure offset is necessary for events, given that offset can
change arbitrarily. WDYT? It seems to me that once an event has
been tied to a particular time in a particular time zone that
Org's job is to take into account changes to that timezone, such
as DST and arbitrary legislation. These changes in the event's
timezone need to be propagated through the schedule for each user,
so it is possible to synchronize local timestamps around the
globe.
All the best,
Tom
--
Thomas S. Dye
https://tsdye.online/tsdye
next prev parent reply other threads:[~2023-01-22 6:52 UTC|newest]
Thread overview: 328+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-13 8:56 [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Daryl Manning
2023-01-13 12:51 ` Tim Cross
2023-01-14 6:27 ` Daryl Manning
2023-01-14 12:46 ` Jean Louis
2023-01-14 11:18 ` Ihor Radchenko
2023-01-14 11:26 ` Daryl Manning
2023-01-14 11:42 ` Ihor Radchenko
2023-01-15 5:11 ` Max Nikulin
2023-01-15 13:41 ` Ihor Radchenko
2023-01-16 16:43 ` Max Nikulin
2023-01-16 18:37 ` Ihor Radchenko
2023-01-17 17:40 ` Max Nikulin
2023-01-18 9:59 ` Ihor Radchenko
2023-01-18 16:25 ` Jean Louis
2023-01-18 16:24 ` [SOLUTION] " Jean Louis
2023-01-20 10:57 ` Ihor Radchenko
2023-01-20 11:29 ` Daryl Manning
2023-01-20 11:36 ` Ihor Radchenko
2023-01-20 15:10 ` Daryl Manning
2023-01-20 11:39 ` Fraga, Eric
2023-01-20 11:48 ` Ihor Radchenko
2023-01-21 12:55 ` Jean Louis
2023-01-21 13:41 ` Ihor Radchenko
2023-01-21 9:21 ` Ihor Radchenko
2023-01-21 10:14 ` Max Nikulin
2023-01-22 11:49 ` Ihor Radchenko
2023-01-20 22:51 ` Tim Cross
2023-01-14 13:03 ` Tim Cross
2023-01-14 13:22 ` Ihor Radchenko
2023-01-15 19:10 ` Jean Louis
2023-01-16 11:21 ` Ihor Radchenko
2023-01-16 11:30 ` Daryl Manning
2023-01-16 11:39 ` Ihor Radchenko
2023-01-16 15:43 ` Daryl Manning
2023-01-16 19:07 ` Ihor Radchenko
2023-01-16 19:22 ` Robert Horn
2023-01-16 19:41 ` Ihor Radchenko
2023-01-16 20:47 ` Robert Horn
2023-01-16 21:02 ` Tom Gillespie
2023-01-16 21:48 ` Robert Horn
2023-01-17 8:53 ` Ihor Radchenko
2023-01-17 3:55 ` Daryl Manning
2023-01-17 8:22 ` Tim Cross
2023-01-17 9:15 ` Ihor Radchenko
2023-01-17 9:45 ` Tim Cross
2023-01-18 9:15 ` Ihor Radchenko
2023-01-18 11:43 ` Tim Cross
2023-01-18 12:02 ` Ihor Radchenko
2023-01-18 21:16 ` Tim Cross
2023-01-19 5:29 ` Jean Louis
2023-01-19 6:25 ` Thomas S. Dye
2023-01-19 14:17 ` Jean Louis
2023-01-19 15:55 ` Thomas S. Dye
2023-01-21 13:10 ` Jean Louis
2023-01-21 16:23 ` Thomas S. Dye
2023-01-21 13:50 ` Jean Louis
2023-01-21 14:31 ` Max Nikulin
2023-01-21 16:55 ` Thomas S. Dye
2023-01-19 7:23 ` Tim Cross
2023-01-19 14:32 ` Jean Louis
2023-01-19 20:09 ` Tim Cross
2023-01-19 23:02 ` Thomas S. Dye
2023-01-19 23:51 ` Tim Cross
2023-01-20 0:24 ` Thomas S. Dye
2023-01-20 3:46 ` Tim Cross
2023-01-20 6:14 ` Thomas S. Dye
2023-01-27 6:06 ` Sterling Hooten
2023-01-27 6:09 ` Daryl Manning
2023-01-27 9:54 ` Jean Louis
2023-01-27 21:04 ` Tim Cross
2023-01-29 4:09 ` Jean Louis
2023-01-29 6:21 ` Thomas S. Dye
2023-01-29 6:46 ` Daryl Manning
2023-01-29 14:10 ` Ihor Radchenko
2023-01-30 19:37 ` Jean Louis
2023-01-31 0:53 ` Thomas S. Dye
[not found] ` <0597910b-9b01-3c0c-5d06-da171e0de4cd@gmx.at>
2023-01-31 6:08 ` Jean Louis
2023-01-29 6:31 ` Max Nikulin
2023-01-30 20:36 ` Jean Louis
2023-01-30 20:38 ` Jean Louis
2023-01-29 20:26 ` Tim Cross
2023-01-30 20:55 ` Jean Louis
2023-01-30 21:54 ` Tim Cross
2023-01-31 7:04 ` Jean Louis
2023-01-31 8:14 ` Max Nikulin
2023-01-31 13:02 ` Jean Louis
2023-01-27 11:09 ` Ihor Radchenko
2023-01-27 12:49 ` Sterling Hooten
2023-01-27 13:00 ` Ihor Radchenko
2023-01-27 15:03 ` Jean Louis
2023-01-30 13:08 ` Ihor Radchenko
2023-01-27 20:58 ` Tim Cross
2023-01-30 11:25 ` Greg Minshall
2023-01-31 11:48 ` [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Ihor Radchenko
2023-01-31 12:19 ` Daryl Manning
2023-01-31 12:41 ` Ihor Radchenko
[not found] ` <CAL9aZksf8AGF=dXg0KAtLPyu1ATt1fLpvdsjN6GMCuK2KRQ56w@mail.gmail.com>
2023-01-31 13:33 ` Ihor Radchenko
2023-01-31 13:22 ` Jean Louis
2023-01-31 13:46 ` Ihor Radchenko
2023-01-31 19:59 ` Jean Louis
2023-02-01 12:42 ` Ihor Radchenko
2023-02-01 15:28 ` Jean Louis
2023-02-01 16:30 ` Ihor Radchenko
2023-01-31 20:12 ` Jean Louis
2023-02-01 5:46 ` tomas
2023-02-01 7:29 ` Jean Louis
2023-02-01 7:52 ` Tim Cross
2023-02-01 8:32 ` Jean Louis
2023-02-01 8:46 ` Ihor Radchenko
2023-02-01 9:38 ` Tim Cross
2023-02-01 10:15 ` Ihor Radchenko
2023-02-01 14:53 ` Jean Louis
2023-02-01 16:36 ` Ihor Radchenko
2023-02-01 10:46 ` Max Nikulin
2023-02-01 14:43 ` Jean Louis
2023-02-01 16:45 ` Ihor Radchenko
2023-02-02 3:05 ` Max Nikulin
2023-02-02 8:59 ` Ihor Radchenko
2023-02-01 9:40 ` [POLL] Proposed syntax for timestamps with time zone info Stefan Nobis
2023-02-01 9:45 ` Ihor Radchenko
2023-02-01 14:38 ` [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Jean Louis
2023-02-01 16:50 ` Ihor Radchenko
2023-02-03 15:48 ` [POLL] Proposed syntax for timestamps with time zone info Stefan Nobis
2023-02-04 5:07 ` Jean Louis
2023-02-01 9:06 ` Stefan Nobis
2023-02-01 9:20 ` tomas
2023-02-01 9:48 ` Stefan Nobis
2023-10-29 1:04 ` Jean Louis
2023-02-06 15:34 ` Marcin Borkowski
2023-02-06 17:03 ` tomas
2023-02-07 21:08 ` Jean Louis
2023-10-29 1:02 ` Jean Louis
2023-02-01 7:00 ` [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Thomas S. Dye
2023-02-01 7:41 ` Jean Louis
2023-01-31 17:56 ` [POLL] Proposed syntax for timestamps with time zone info Fraga, Eric
2023-01-31 18:13 ` Ihor Radchenko
2023-01-31 18:22 ` Fraga, Eric
2023-01-31 18:56 ` [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Greg Minshall
2023-02-01 12:48 ` Ihor Radchenko
2023-02-01 12:52 ` tomas
2023-02-02 4:49 ` Greg Minshall
2023-01-31 20:41 ` Tim Cross
2023-01-31 23:50 ` Samuel Wales
2023-02-01 13:01 ` Ihor Radchenko
2023-02-04 22:33 ` Samuel Wales
2023-02-04 22:49 ` Samuel Wales
2023-02-05 10:38 ` Ihor Radchenko
2023-02-01 11:56 ` Christian Moe
2023-02-01 12:20 ` Ihor Radchenko
[not found] ` <87o7qdsf7h.fsf@christianmoe.com>
2023-02-01 13:26 ` POSIX TS spec reverses the meaning of TZ offset compared to ISO (was: [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda)) Ihor Radchenko
2023-02-01 13:51 ` tomas
2023-02-01 21:57 ` POSIX TS spec reverses the meaning of TZ offset compared to ISO (was: [POLL] Proposed syntax for timestamps with time zone info Heinz Tuechler
2023-02-01 22:50 ` Samuel Wales
2023-02-02 9:01 ` Ihor Radchenko
2023-02-02 3:22 ` Max Nikulin
2023-02-02 7:45 ` POSIX TS spec reverses the meaning of TZ offset compared to ISO Heinz Tuechler
2023-02-02 8:33 ` tomas
2023-02-02 9:37 ` Heinz Tuechler
2023-02-04 15:44 ` Max Nikulin
2023-02-02 5:35 ` POSIX TS spec reverses the meaning of TZ offset compared to ISO (was: [POLL] Proposed syntax for timestamps with time zone info tomas
2023-02-02 8:56 ` Ihor Radchenko
2023-02-01 15:16 ` POSIX TS spec reverses the meaning of TZ offset compared to ISO (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Max Nikulin
2023-02-02 8:34 ` Ihor Radchenko
2023-02-02 13:59 ` Max Nikulin
2023-02-02 14:06 ` Ihor Radchenko
2023-02-01 15:41 ` [POLL] Proposed syntax for timestamps with time zone info " Jean Louis
2023-02-02 8:38 ` Ihor Radchenko
2023-02-03 11:31 ` Jean Louis
2023-02-04 10:58 ` Ihor Radchenko
2023-02-04 19:32 ` Jean Louis
2023-02-05 9:14 ` Ihor Radchenko
2023-02-02 3:46 ` Timothy
2023-02-02 9:12 ` Ihor Radchenko
2023-02-02 9:12 ` Timothy
2023-02-02 9:20 ` Ihor Radchenko
2023-02-02 9:27 ` Timothy
2023-02-02 9:38 ` [POLL] Proposed syntax for timestamps with time zone info Stefan Nobis
2023-01-30 12:30 ` [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Ihor Radchenko
2023-01-30 15:30 ` Greg Minshall
2023-01-30 15:38 ` Ihor Radchenko
2023-01-30 15:48 ` Greg Minshall
2023-01-20 4:03 ` Max Nikulin
2023-01-20 5:39 ` Tim Cross
2023-01-20 7:28 ` Max Nikulin
2023-01-20 8:11 ` Tim Cross
2023-01-20 15:29 ` Max Nikulin
2023-01-20 22:56 ` Tim Cross
2023-01-20 9:35 ` Fraga, Eric
2023-01-20 10:48 ` Ihor Radchenko
2023-01-20 6:46 ` Thomas S. Dye
2023-01-20 7:34 ` Max Nikulin
2023-01-20 8:17 ` Tim Cross
2023-01-20 12:17 ` Max Nikulin
2023-01-20 16:09 ` Thomas S. Dye
2023-01-20 16:56 ` Max Nikulin
2023-01-20 20:37 ` Thomas S. Dye
2023-01-21 0:14 ` Tim Cross
2023-01-21 0:37 ` Thomas S. Dye
2023-01-21 5:53 ` Max Nikulin
2023-01-21 15:55 ` Thomas S. Dye
2023-01-22 12:14 ` Max Nikulin
2023-01-22 13:35 ` Thomas S. Dye
2023-01-22 14:09 ` Max Nikulin
2023-01-20 23:38 ` Tim Cross
2023-01-21 6:21 ` Max Nikulin
2023-01-21 21:29 ` Tim Cross
2023-01-22 5:50 ` UTC or not UTC for timestamps in the past ([FEATURE REQUEST] Timezone support in org-mode) Max Nikulin
2023-01-22 6:17 ` Thomas S. Dye [this message]
2023-01-22 8:35 ` Max Nikulin
2023-01-22 16:54 ` Thomas S. Dye
2023-01-23 6:28 ` Jean Louis
2023-01-23 16:04 ` Thomas S. Dye
2023-01-24 2:34 ` Max Nikulin
2023-01-24 2:44 ` Thomas S. Dye
2023-01-24 4:48 ` Max Nikulin
2023-01-24 19:18 ` Jean Louis
2023-01-24 9:34 ` Ihor Radchenko
2023-01-24 16:41 ` Thomas S. Dye
2023-01-26 15:37 ` Max Nikulin
2023-01-26 16:31 ` Thomas S. Dye
2023-01-27 21:21 ` Tim Cross
2023-01-22 7:48 ` Tim Cross
2023-01-24 17:09 ` Max Nikulin
2023-01-24 19:20 ` Jean Louis
2023-01-24 20:50 ` Tim Cross
2023-01-19 10:35 ` [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Ihor Radchenko
2023-01-19 17:57 ` Alexander Adolf
2023-01-21 13:51 ` Jean Louis
2023-01-18 17:09 ` Max Nikulin
2023-01-17 8:45 ` Ihor Radchenko
2023-01-19 16:56 ` Robert Horn
2023-01-19 17:44 ` Alexander Adolf
2023-01-19 17:48 ` Alexander Adolf
2023-01-17 15:37 ` Jean Louis
2023-01-18 9:29 ` Ihor Radchenko
2023-01-18 16:11 ` Jean Louis
2023-01-18 21:31 ` Tim Cross
2023-01-19 10:40 ` Ihor Radchenko
2023-01-17 17:28 ` Max Nikulin
2023-01-17 19:49 ` Ihor Radchenko
2023-01-18 16:21 ` Jean Louis
2023-01-18 16:20 ` Jean Louis
2023-01-20 16:27 ` Max Nikulin
2023-01-19 17:33 ` Alexander Adolf
2023-01-16 20:25 ` Tim Cross
2023-01-17 9:07 ` Ihor Radchenko
2023-01-17 15:24 ` Jean Louis
2023-01-18 9:34 ` Ihor Radchenko
2023-01-18 16:07 ` Jean Louis
2023-01-19 10:43 ` Ihor Radchenko
2023-01-19 14:37 ` Jean Louis
2023-01-15 20:43 ` Jean Louis
2023-01-16 11:25 ` Ihor Radchenko
2023-01-17 15:19 ` Jean Louis
2023-01-18 9:38 ` Ihor Radchenko
2023-01-16 5:01 ` Tom Gillespie
2023-01-16 12:31 ` Ihor Radchenko
2023-01-16 20:32 ` Tim Cross
2023-01-16 20:51 ` Tom Gillespie
2023-01-17 9:12 ` [FR] Allow BC years in timestamps (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Ihor Radchenko
2023-01-13 19:06 ` [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Jean Louis
2023-01-14 7:12 ` Max Nikulin
2023-01-14 9:32 ` Tim Cross
2023-01-14 11:08 ` Russell Adams
2023-01-14 11:35 ` Ihor Radchenko
2023-01-14 12:00 ` Russell Adams
2023-01-14 12:16 ` [FR] Allow end date and max repeat count for timestamps with repeaters (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Ihor Radchenko
2023-01-15 1:09 ` Samuel Wales
2023-01-15 13:45 ` Ihor Radchenko
2023-01-15 23:49 ` Samuel Wales
2023-01-15 23:53 ` Samuel Wales
2023-01-16 13:01 ` Ihor Radchenko
2023-01-14 12:19 ` [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Ihor Radchenko
2023-01-14 12:21 ` Russell Adams
2023-01-14 12:31 ` Ihor Radchenko
2023-01-14 11:30 ` Ihor Radchenko
2023-01-14 14:09 ` Tim Cross
2023-01-14 14:38 ` Ihor Radchenko
2023-01-14 14:48 ` tomas
2023-01-14 15:05 ` Ihor Radchenko
2023-01-14 16:50 ` tomas
2023-01-14 17:06 ` Ihor Radchenko
2023-01-14 17:13 ` tomas
2023-01-15 19:54 ` Jean Louis
2023-01-14 21:52 ` Tim Cross
2023-01-15 13:52 ` Ihor Radchenko
2023-01-20 14:34 ` Alexander Adolf
2023-01-15 20:03 ` Jean Louis
2023-01-15 19:52 ` Jean Louis
2023-01-16 13:11 ` Ihor Radchenko
2023-01-14 20:56 ` Tim Cross
2023-01-15 20:24 ` Jean Louis
2023-01-15 4:37 ` Max Nikulin
2023-01-15 5:03 ` Max Nikulin
2023-01-15 20:28 ` Jean Louis
2023-01-16 13:17 ` Ihor Radchenko
2023-01-14 11:55 ` Max Nikulin
2023-01-14 13:50 ` Tim Cross
2023-01-14 16:50 ` Max Nikulin
2023-01-14 20:30 ` Tim Cross
2023-01-15 4:00 ` Max Nikulin
2023-01-15 7:53 ` Tim Cross
2023-01-15 19:26 ` Jean Louis
2023-01-16 13:20 ` Ihor Radchenko
2023-01-15 14:00 ` Ihor Radchenko
2023-01-14 13:08 ` Jean Louis
2023-01-14 16:58 ` Max Nikulin
2023-01-14 19:43 ` Tim Cross
2023-01-15 6:37 ` tomas
2023-01-15 14:07 ` Ihor Radchenko
2023-01-15 20:43 ` Tim Cross
2023-01-16 5:20 ` Tom Gillespie
2023-01-16 13:29 ` Ihor Radchenko
2023-01-16 17:30 ` Tom Gillespie
2023-01-16 17:53 ` Ihor Radchenko
2023-01-16 13:27 ` Ihor Radchenko
2023-01-15 19:14 ` Jean Louis
2023-01-16 4:20 ` Max Nikulin
2023-01-15 19:12 ` Jean Louis
2023-01-14 5:14 ` Samuel Wales
2023-01-14 5:51 ` Tom Gillespie
2023-01-14 6:40 ` tomas
2023-01-26 15:24 ` Org mode timestamps on the Moon ;] (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Ihor Radchenko
2023-01-26 16:08 ` Org mode timestamps on the Moon ;] Fraga, Eric
2023-01-26 16:28 ` Thomas S. Dye
2023-01-26 23:40 ` Org mode timestamps on the Moon ;] (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda) Tom Gillespie
2023-01-30 10:13 ` Org mode timestamps on the Moon ; ] " Greg Minshall
2023-01-30 13:05 ` Org mode timestamps on the Moon ;] " Ihor Radchenko
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