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

[Thomas S. Dye]

Aloha Max,

Max Nikulin <manikulin@gmail.com> writes:

> On 20/01/2023 23:09, Thomas S. Dye wrote:
> > Max Nikulin writes:
> > Now, if Amsterdam's timezone 
> > arbitrarily changes its relation to UTC before the conference 
> > takes place,
> > then everyone who participates in the conference must notice 
> > this (or miss the
> > start of the conference).
>
> My point is that if timestamp is stored in UTC than it becomes 
> incorrect in the
> case of time offset change. If such timestamp is stored as local 
> time + time
> zone identifier then application presenting the timestamp to 
> users will show
> correct time as soon as zoneinfo data is updated.
>
> > A virtual conference is organized by someone in Amsterdam, who 
> > sets a start
> > time corresponding to 9AM in Amsterdam at a date some years in 
> > the future and
> > invites participants from all over the world.  Now, if 
> > Amsterdam's timezone
> > arbitrarily changes its relation to UTC before the conference 
> > takes place,
> > then must everyone notice this?  Or, should Org, from the time 
> > the arbitrary 
> > change is made public, simply adjust the conference time for 
> > all the
> > participants in the Amsterdam timezone?
>
> Both variants are possible and a planning application should 
> support them. It is
> matter of negotiation between the committee and the 
> participants. Timestamp
> should be stored in UTC only in one case.

Agreed.  So, IIUC, there are three cases:

1) Occurrence, where the timestamp includes UTC;
2) Event relative to user, where the timestamp does not include 
UTC or a time zone; and 
3) Event not relative to user, where the timestamp includes the 
relevant time zone.

For completeness, Case 3 might benefit from a procedure to change 
the relevant time zone.  For instance, when the boss has scheduled 
time for you at 9:00 AM her time, but doesn't know where she will 
be on that day.

hth,
Tom

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