TIMEZONE property for ical export

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> Hello,
>
> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> Hey, now's the time to bring up something I've wanted to do for
>> a while:
>
> I think this deserves its own thread.

Here we go!

>> adding support for per-entry timezones to the ical export. 
>
> It sounds good.
>
>> I've attached a draft patch that shows what I mean. Basically you give
>> an entry a TIMEZONE property in the tz database format (eg
>> "Europe/London") and it will pass that on to the DTSTART/DTEND
>> properties.
>>
>> I suppose it would also be possible to have separate properties for
>> start and end timezones, then we could do plane trips!
>
> Right. But since Org doesn't support time zones, the usefulness may be
> limited.

Yeah, I'm not convinced it's worthwhile. It's really only the one
use-case, though it would be handy.

Out of curiosity, what's your stance on supporting time zones in Org's
timestamps? It would be an enormous amount of work, obviously, but in
principle?

>> +When optional argument TZ is non-nil, timezone data time will be
>> +added to the timestamp.  It can be the string \"UTC\", to use UTC
>> +time, or a string in the IANA TZ database
>> +format (e.g. \"Europe/London\").  In either case, the value of
>> +`org-icalendar-date-time-format' will be ignored."
>
> I suggest to have symbol t as an equivalent to "UTC", for compatibility
> with, e.g., ZONE in `format-time-string'.

That's pretty much what it was before I messed with it, and I was a
little confused because no callers of `org-icalendar-convert-timestamp'
ever used the optional fourth argument at all. My thinking was that
users might want to explicitly set the timezone to "UTC". To be honest
I'm not sure why they would, but I also don't know why we'd accept t
when nothing uses it. I found the whole handling of utc-or-not a bit
confusing. What do you think?

Thanks,
Eric