Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda

[Jean Louis <bugs@gnu.support>]

* Ihor Radchenko <yantar92@posteo.net> [2023-01-16 22:08]:
> 1. Time (YYYY-MM-DD HH:MM) not continuous and may change arbitrarily at
>    certain times a year or in future or in the past:

I am sure that system library must be responsible to know those
changes. It is not for Org. 

So the calculation which transforms +1 time zone to -5 time zone shall
be done by using system libraries which are supposed to have those
options. I have no idea if they have.

> 2. There might be arbitrary time gaps due to time transition, including

>    - One hour back during DST transition (northern and southern
>      hemispheres do the transitions in opposite directions)
>    - Multiple days skipped (Samoa skips a whole day during DST
>      transition)

Interesting, but I still think that shall be in system library, and
system libraries shall provide calculation functions. 

Does that exist in C library?

> 3. We cannot assume that the same geographical area has fixed time zone
>    even at given point of time:
>    - Palestinian/Israeli people follow different time zones in the
>      contested territories

They may, sure, I can also follow my own, but Org and system libraries
shall use internationally accepted norms.

> 4. Great Britain had new year on March 25 until 16th century
>    (March 24, 1000 -> (+1 day) March 25, 1001)

Of course, that is why December is called by that way, as the tenth
month, not twelfth. That may be part of representation of calendar,
but because it is history, it is not so important for us in future.

> 5. Leap seconds! 23:59:59 -> 23:59:60 -> 00:00:00, according to
>    astronomical Earth observations

Should be part of C library to observe those things.

-- 
Jean

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