On 1/31/24 11:39, Michael H Deckers wrote:
There's no such feature in tzcode. I don't recall such a feature being discussed - could you point us at any thread in the archive?
From NEWS for release 2014b:
Changes affecting code
'zic' and 'localtime' no longer reject locations needing four transitions per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
That merely causes zic to accept .zi input containing four transitions per year for the foreseeable future. Input like this, for example: Rule Troll 2005 max - Mar 1 1:00u 1:00 +01 Rule Troll 2005 max - Mar lastSun 1:00u 2:00 +02 Rule Troll 2005 max - Oct lastSun 1:00u 1:00 +01 Rule Troll 2004 max - Nov 7 1:00u 0:00 +00 Zone Antarctica/Troll 0 - -00 2005 Feb 12 0:00 Troll %s (This isn't in tzdata, but it could be once we can assume tzcode 2014b or later.) When zic sees input like this, it generates a big TZif file with explicit transitions out to the year 2407 (2005 + 402 years). The big TZif file does not have a TZ string, because no TZ string can represent all these transitions. Previous to 2014b, zic would reject this .zi input; and pre-2014 localtime would not always work on the big TZif files that 2014b-or-later zic generates with this .zi input. Although it might be nice for some future RFC 8536 edition to handle Troll, and for tzcode to support it, that's not in the current draft.