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* Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda
@ 2023-01-15 19:16 Thomas S. Dye
  0 siblings, 0 replies; 213+ messages in thread
From: Thomas S. Dye @ 2023-01-15 19:16 UTC (permalink / raw)
  To: emacs-orgmode

Aloha all,

IIUC, timestamps in Org might be used to track two things: events 
and occurrences.

An event refers to a particular region of space/time, in Org's 
case the space/time occupied by the user, regardless of which time 
zone the user occupies.  An event might be "Brush teeth before 
bed" set for 10:00 PM, which the user would want to make happen at 
that time, regardless of the time of day in the timezone in which 
the timestamp was applied to the event.

An occurrence refers to changes in the nature and relations of 
substances at a time.  It takes place in absolute time in order to 
avoid circularity.  An occurrence might be "Attend virtual 
meeting" set for 9:00 AM on a certain day, which the user would 
want to make happen at 9:00 AM on that day in the time zone where 
the timestamp was applied to the occurrence, regardless of the 
time zone where the user happened to be.

I found this distinction in a book called On Truth by Frank 
Ramsey, that was unfinished at his untimely death at age 26. 
"Event" and "occurrence" were Ramsey's suggestions.  He seemed to 
like "event", but thought "occurrence" would work, though it might 
be improved.

I enjoy having terms for these two kinds of happenings and I'm 
hopeful you'll find them useful, too.

All the best,
Tom

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


^ permalink raw reply	[flat|nested] 213+ messages in thread
* Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda
@ 2023-01-28  6:26 Max Nikulin
  0 siblings, 0 replies; 213+ messages in thread
From: Max Nikulin @ 2023-01-28  6:26 UTC (permalink / raw)
  To: Sterling Hooten; +Cc: emacs-orgmode

Sterling, thank you very much for the list of references. I was not 
aware of EDTF activity or the proposal for JavaScript.

I do not mind to have better precision for timestamps. Minutes are too 
coarse. However I would consider with low priority.

I would prefer to postpone some discussions now. At the current moment 
just be aware than one more person may have another opinion. Redundant 
fields are useful for humans, in addition, they allow to detect 
inconsistency. Date and time format with spaces are more friendly to 
humans as well. "T" hampers readability. So I feel some kind of internal 
conflict trying to achieve following standards, backward compatibility, 
and human readability simultaneously. I am unsure what is the proper 
solution.

The following is what I consider as more serious issues:

On 27/01/2023 13:06, Sterling Hooten wrote:
>    Duration (object)
>          as a quantity characterizing a time interval. These can be
>          written in different formats.

Interval, duration, elapsed time are tricky. I do not have preferences 
whose definitions we should follow. Just an example: (info "(libc) Time 
Basics") https://www.gnu.org/software/libc/manual/html_node/Time-Basics.html

Notice that 1 day does not necessary means 24 hours. Depending on 
starting day (e.g. before DST) other relations may be used, either 23 or 
25 hours (usually). It is still 1 day. The way to specify interval 
should be chosen depending on application.

Another case is January, 31 + 1 month. It actually may mean last day of 
January, so expected result may be February, 28 or 29. This case 
February, 28 + 1 month (the same interval) is March, 31.

>    Local system time
>          Local system time is determined by applying the system's time
>          zone offset and year offset values to UTC. The Time of day
>          system value displays the local system time. Local system time
>          and system time are used interchangeably.

"System time" is often used in the sense of hardware clock and 
originated from the times when DOS or Windows required local time.

>    Time Zone
>          A place/region.

Do you consider e.g. Etc/GMT-8 or UTC itself as a time zone?

>    Floating time
>          A wall time value without time zone or offset information. E.g.,
>          2023-01-24 or 6:45pm.

A potential source of confusion with timestamp in seconds since epoch as 
a floating point number, see `float-time'. (info "(elisp) Time of Day") 
https://www.gnu.org/software/emacs/manual/html_node/elisp/Time-of-Day.html#index-float_002dtime

> Org must first support
> fixed/absolute time instead of just floating time.

Am I wright "in addition" is applicable here in the place of "instead"?

> • Design and implement the time zone aware calendar system This is a
>    separate project.

Will not such decision ruin "every Wednesday at 3:00 PM" at the moment 
of DST transition? I would vote that IANA DB should be used for 
calculations despite I have not seen a library with perfect API. Though 
libc with some tricks may allow to do most of tasks. (Even in presence 
of limitations such as unavailable identifier of system time zone.) This 
is the main point of my disagreement. If real time zones are not 
implemented from the beginning then the will be never supported, so the 
whole bunch of code will be requiring throwing away while keeping 
support of some formats to read old files.

>    • We are able to defer to experts and 35 years of knowledge rather
>      than debate among ourselves

Experts may generate enough pain such as requirement to not support IANA 
timezone DB as it was in EcmaScript 5 (Chrome followed it, but in 
Firefox conversion between local time worked correctly).


^ permalink raw reply	[flat|nested] 213+ messages in thread
* [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda
@ 2023-01-13  8:56 Daryl Manning
  2023-01-13 12:51 ` Tim Cross
                   ` (2 more replies)
  0 siblings, 3 replies; 213+ messages in thread
From: Daryl Manning @ 2023-01-13  8:56 UTC (permalink / raw)
  To: Org-mode

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Following on from thread at
https://www.reddit.com/r/orgmode/comments/zrppqw/

[First off, I just wanted to say thank you to everyone that works on
org-mode. It is a wonder.]

While I realize a few kicks at this can may have been taken, I wanted to
(re-)propose Timezone support in org-mode. The world is much less local
these days and we're all more remote and coordinating globally these days.

*Background*

1. org-time-stamp-formats TZ currently only affects display and exports
2. org-agenda itself is not TZ aware
3. Several discussions on this have taken place over time
4. Concerns raise included breaking backwards compatibility

*Proposal*

1. org-mode sets an optional variable (org-timezone-aware t) which enables
TZ
2. org-agenda needs a way to determine which timezone it is in
3. Once enabled, any timestamp not exhibiting a TZ in it is considered
"local time" wherever that is (I do not think UTC would work for this)
4. org-agenda can calc local based on TZ differences

I understand this is by no means trivial and quite gnarly with DST and such
to figure out but I do believe libs exists to deal with that heavy lifting.
Currently, it does feel like a hole in org-mode as a 21st century organizer
(disclaimer: digital nomading so might feel it more keenly). Also, just
interested in making org-mode a more awesome tool for everybody.

I'd love an understanding of the alluded to reservations raised in the
reddit thread and in the mailing list threads mentioned that the format
change might break things (I was unsure if that was referring to say, how
time ranges were handled, or how say date ranges got dealt with (for
example, say a flight from Singapore to Vancouver which takes off in one
time zone and lands in another - something that is often in my cal.).

thanks!
Daryl.

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^ permalink raw reply	[flat|nested] 213+ messages in thread

end of thread, other threads:[~2023-01-31 13:44 UTC | newest]

Thread overview: 213+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-01-15 19:16 [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Thomas S. Dye
  -- strict thread matches above, loose matches on Subject: below --
2023-01-28  6:26 Max Nikulin
2023-01-13  8:56 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
2023-01-20 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
2023-01-30 12:30                                                               ` 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
2023-01-19 10:35                                           ` 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
2023-01-13 19:06 ` 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 12:19             ` 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

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