On Wed, Sep 7, 2016 at 4:52 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
>
> On 09/07/2016 01:03 PM, Alexander Belopolsky wrote:
>>
>> That's clear, but adding an option to zic to generate timezone data in tzdist format may not be out of reach.
>
>
> vzic already does that, no?

Not really. As far as I can tell, vzic produces a single RFC 2445 vztimezone specification for each IANA zone. All generated .ics files have the same DTSTART set to 19700101T000000 and RFC 7808 TZUNTIL property is not supported at all.

> Do we need to reinvent that wheel?

For some reason vzic author had to reinvent the wheel and write his own zone file parser. This part does not need to be reinvented. Since zic already knows how to translate rules to POSIX TZ string format, translating to iCalendar RRULE does not seem to require a lot of code. However, what I had in mind was that zic could implement the RFC 7808 "expand" action <https://tools.ietf.org/html/rfc7808#section-5.4> which is not implemented in vzic.