Re: UTC or not UTC for timestamps in the past ([FEATURE REQUEST] Timezone support in org-mode)

[Ihor Radchenko]

"Thomas S. Dye" <tsd@tsdye.online> writes:

>> I understand above that it is easier understandable when reading
>> [2023-01-22 Sun 08:29@+1100] as it is assumed by poster (I guess 
>> Max)
>> that user will understand that there is +11 hours ahead.
>>
> Yes, the offset here is ambiguous--is it offset from some timezone 
> or from UTC?

It is not ambiguous if the user is familiar with standard time format.
The representation above is derived from
https://en.wikipedia.org/wiki/ISO_8601, which allows the following:

    <time>Z

    If the time is in UTC, add a Z directly after the time without a space.
    Z is the zone designator for the zero UTC offset. "09:30 UTC" is
    therefore represented as "09:30Z" or "T0930Z". "14:45:15 UTC" would be
    "14:45:15Z" or "T144515Z".

    <time>±hh:mm
    <time>±hhmm
    <time>±hh

    The UTC offset is appended to the time in the same way that 'Z' was
    above, in the form ±[hh]:[mm], ±[hh][mm], or ±[hh].

    Negative UTC offsets describe a time zone west of UTC±00:00, where the
    civil time is behind (or earlier) than UTC so the zone designator will
    look like "−03:00","−0300", or "−03".
    
    Positive UTC offsets describe a time zone at or east of UTC±00:00, where
    the civil time is the same as or ahead (or later) than UTC so the zone
    designator will look like "+02:00","+0200", or "+02".

> Here is a proposal for a terminology of events that honors 
> Ramsey's distinction between events and occurrences and hopes to 
> cover all of Org's use cases.
> ...
> ...
> The Org user should be able to toggle timestamp representation. 
> In the case of a no-host event, user might toggle between UTC and 
> local time.  In the case of situated or itinerant event, user 
> might toggle among UTC, local time, and local time at the event 
> site.

Instead of toggling, would it be better to echo the different formats
like eldoc does + mouse-echo?

-- 
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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