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From: Maxim Nikulin <manikulin@gmail.com>
To: emacs-orgmode@gnu.org
Subject: Re: Idea for handling timezones
Date: Sun, 4 Apr 2021 23:06:41 +0700	[thread overview]
Message-ID: <s4co6i$8gk$1@ciao.gmane.io> (raw)
In-Reply-To: <CA+G3_PN5x6wsrw7FM0RV06=6FbUMoaZryKZxxg4tvc_bAgCP=Q@mail.gmail.com>

The notes below are quite general and unrelated to particular message.

On 04/04/2021 07:51, Tom Gillespie wrote:
> 
> followed by a space and then the repeat or delay for example
> [+10000-01-01 10:11:00,992315771-04:00 Sat] or
> [-480-08-20 05:00+01:00]
> or more temporally local
> [2021-03-03 17:43-07:00 Sat]

Just an idea, I do not know if it is feasible and convenient. Have 
anyone considered a kind of src blocks to describe timestamps? Current 
inline syntax is suitable for simple cases, sometimes more details are 
required, some information could be redundant to allow consistency check:

- Date-time in the original form as it appeared in external source (with 
a hint related to particular format e.g. rfc822 date.
- Either it is local time or it is bound to some event as Solar eclipse.
- List if time zones to have notion of local time of all participants of 
an online meeting.
- Location for planned event since there is a chance that existing time 
zone will be split into smaller ones.

A couple of bookmarks to get impression of complexity:
- https://stackoverflow.com/tags/timezone/info
   timezone Tag Info
- 
https://infiniteundo.com/post/25326999628/falsehoods-programmers-believe-about-time
   Falsehoods programmers believe about time
   and follow-ups.

Emacs API is hardly suitable for working with multiple time zones. 
Something could be borrowed from other projects, e.g.
https://howardhinnant.github.io/date_algorithms.html
Low-Level Date Algorithms (C++)
A special attribute has been added in python to deal with local time 
ambiguity around time transitions
https://docs.python.org/3/library/datetime.html#datetime.datetime.fold
https://www.python.org/dev/peps/pep-0495/
PEP 495 -- Local Time Disambiguation

I think, it is a challenge to provide a convenient way to generate 
agenda for a trip across several time zones.

P.S. Raw UNIX timestamp as 1234567890 is convenient for some 
computations but hardly human friendly. UTC date-time 
2009-02-13T23:31:30Z is better. With particular offset 
2009-02-13T22:31:30-01:00 it is equally precise and even more 
convenient. Still neither of such forms are applicable if it is 
scheduled event with fixed local time and offset of particular timezone 
might be changed.



  reply	other threads:[~2021-04-04 16:07 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01  7:40 shironeko
2021-04-02 11:34 ` tomas
2021-04-03  0:36   ` Shironeko
2021-04-03  7:56     ` tomas
2021-04-03  8:03       ` shironeko
2021-04-03  8:30         ` tomas
2021-04-03  9:26           ` Shironeko
2021-04-03 11:23             ` Greg Minshall
2021-04-03 15:00               ` Russell Adams
2021-04-03 18:51                 ` Greg Minshall
2021-04-03 20:06                   ` Samuel Wales
2021-04-03 22:47                   ` Tim Cross
2021-04-04  0:51                     ` Tom Gillespie
2021-04-04 16:06                       ` Maxim Nikulin [this message]
2021-04-23  1:45                         ` Shironeko
2021-04-23  7:54                           ` tomas
2021-04-03 12:43             ` tomas
2021-04-03 12:47               ` Shironeko
2021-04-03 13:20                 ` Shironeko
2021-04-02 23:37 ` Tim Cross
2021-04-03  0:31   ` Samuel Wales
2021-04-03  0:43   ` Shironeko
2021-04-03  0:53     ` Samuel Wales
  -- strict thread matches above, loose matches on Subject: below --
2021-03-31  2:23 Shironeko

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