[tz] data not represented in tzfiles

Paul Eggert eggert at cs.ucla.edu
Sat Sep 7 01:52:03 UTC 2013

Zefram wrote:
> For example, suppose you have a rule (not expressible in POSIX form)
> applying from 2012 onwards that has transitions in March and September,
> plus some one-off transitions in November 2013.

The idea behind the recent changes is that all the rules
one can write can be expressed in extended-POSIX
form; if that's good enough, then the scenario you describe
is no longer possible.

Can you supply an example illustrating the problem?
Does this have anything to do with yearistype.sh?

Come to think of it, there is one situation the
zic code doesn't cover -- perpetual DST.
The code claims that this is a POSIX no-no, but on
further thought that's incorrect; for example, for
San Luis's perpetual-DST (before the database changed
yesterday) we can use TZ='WART4WARST,J1/0,J365/24'.
I'll come up with a patch to fix this.

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