Re: [POLL] Proposed syntax for timestamps with time zone info (was: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda)

[Ihor Radchenko]

Timothy <orgmode@tec.tecosaur.net> writes:

> This functions well, however I see a potential to be confusing at a glance 
> here.
> Consider the visual similarity of 10:30 to 11:00 in local time and 10:30 in
> UTC-11, and the combination of both.
>
> ┌────
> │ [2022-11-12 10:30-11:00]
> │ [2022-11-12 10:30-1100]
> │ [2022-11-12 10:30-11:00-1100]
> └────

Note that an alternative is 

 [2022-11-12 10:30-11:00]
 [2022-11-12 10:30-11]
 [2022-11-12 10:30-11:00-11]

which is much less confusing.

> I’d be inclined to put the UTC offset together with the time zone name if
> possible. Do you think something along the lines of `@-1100,America/Anchorage'
> could be viable? I’d think that would reduce the chance of confusion.
>
> ┌────
> │ [2022-11-12 10:30-11:00]
> │ [2022-11-12 10:30 @-1100]
> │ [2022-11-12 10:30-11:00 @-1100]
> └────

This might be an option.
A slight disadvantage is more verbose syntax for simple timestamps like

 [2022-11-12 10:30+02]
 [2022-11-12 10:30 @+02]

>>    2022-11-12 12:00+07 @!Asia/Singapore
>>
>>    Org will calculate the internal time for both +07 offset and
>>    Asia/Singapore time zone. If they do not match, Org will issue a
>>    warning. The offset will still be preferred if we have to proceed.
>>
>>    This can be useful when planning future meetings and sending Org file
>>    with a timestamp to someone else, potentially with obsolete tzdb.
>
> I like the way that combining these features works, but I do wonder if perhaps
> warning when these two bits of information don’t match should be the default
> behaviour, and the `!' used to specify which of them should be prioritised?

I am not sure if it is a good idea.

> It also occurs to me that this proposed behaviour might be easier with a 
> single
> `@TZINFO' form as I mentioned earlier, e.g.
>
> ┌────
> │ [2022-11-12 12:00 @+07,Asia/Singapore]  # warn when mismatch
> │ [2022-11-12 12:00 @+07,!Asia/Singapore] # use Asia/Singapore over +07

 Consider the requests about time zone abbreviations. Without "always
 warn", we can do

 [2022-11-12 12:00 @+08,CST]

 with CST being ambiguous (and also not supported by `encode-time').


-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
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