I agree... TZ is optionally defined in a timestamp otherwise understood to be "local".

I'd just be excited to have us run through the basic use cases and then see some more "tricky" ones. I imagine there are things we'd just have to say... too tricky for (eg. flight takes off in one TZ and range allows it to land in timezone... stuff like that might be tricky.).

So, is the TS syntax you've described accepted and canonical now with org-mode? 

Daryl.



On Mon, Jan 16, 2023 at 6:39 PM Ihor Radchenko <yantar92@posteo.net> wrote:
Daryl Manning <daryl@wakatara.com> writes:

> I think timezone you're in should be declared globally, surely?  And then
> defined in the timestamp?

It is always defined globally on OS level. In POSIX-complaint OSes, it is
TZ. Emacs obeys POSIX and time zone settings in other OSes. We don't
need anything special for it.

As for time zone in timestamps - it must be optional. Timestamps with
time zone will use that time zone. Timestamps without time zone will use
"default" time zone - be it OS time zone or whatever custom time zone
setting we come up with in future. This "default" time zone approach is
both useful for things like "brush teeth in 10pm in the evening" and
also, more importantly, for backwards compatibility.

> The use cases for per file or even per-heading tz specifying seems very low
> imho (and introducing a lot more complexity.).

Sure. As I mentioned in another message, not having these features should
not stop us from merging whatever working time zone code we can come up
with. They will be nice to have though.

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