Re: Two problems with export to Google calendar

[Ihor Radchenko <yantar92@posteo.net>]

Max Nikulin <manikulin@gmail.com> writes:

> The TZ environment variable is not set and that is the issue. Otherwise 
> the .ics file would have
>
> X-WR-TIMEZONE:Europe/London
>
> The problem is that there is no API to get time zone identifier in elisp 
> because such function is missed in libc. It is possible to get only 
> BST/GMT (depending on current season).
>
> Identifiers like Europe/London allows to get history of time 
> transitions. (format-time-string "%z %Z") and (current-time-zone) may 
> only report time offset and ambiguous abbreviation at particular moment. 
> Return values of these functions may vary for different timestamps in 
> the calendar file. If list of time zones were available then it would be 
> possible to iterate over it and to match particular time zone by 
> abbreviation and offset for most of zones (perhaps some ambiguity would 
> remain).
>
> Actually `current-time-zone' is an example of fragile API for *current* 
> time. Offset is valid for particular moment. There is no guarantee that 
> offset would not change between obtaining it and applying to a 
> timestamp. So the only safe way of using this function is with the 
> SPECIFIED-TIME argument. In such case *current* in the function name is 
> confusing.
>
> So in my previous message I was considering feasibility of some 
> platform-dependent code to determine time zone when neither TIMEZONE Org 
> file property nor TZ environment are specified.

Thanks for the explanation.

I do not think that it is a problem Org has to solve. Rather Emacs. Or
even libc.

-- 
Ihor Radchenko // yantar92,
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