[tz] Java & Rearguard

[Stephen Colebourne]

On Thu, 6 Jun 2019 at 03:33, Steve Summit <scs at eskimo.com> wrote:
> So perhaps there's an opportunity here to help everyone out
> by trying to promulgate a vocabulary which emphasizes the
> arbitrariness.  Instead of having a "dst" flag which is either
> true or false, what if we had a "kind" field which was a small
> integer from 0 to N-1?  (Of course, internal to tz files, that's
> exactly what we have already.)

In effect, tzdb used to provide (0, 1) for Ireland, now it provides
(1, 0). This was an incompatible API change for the downstream
projects of Java and CLDR. Everything else about the rationale of the
change and the meaning of that data is in many ways not that
important.

Your broader point that an extended/clearer id/flag might be useful is
indeed one way out of the mess. What I argued up-thread was that tzdb
could provide multiple pieces of information - legal dst or not, and
base vs advanced - with the potential to also mark Ramadan type
situations with a different code. But to do so would, IMO probably
need a significant extension to the file format.

Stephen