On Sep 18, 2017, at 10:54 PM, Lord Buddha <lord.buddha@gmail.com> wrote:

Indeed quite probably they have not decided yet. 

Waffling/Rambling...

I know that is/has been the policy to try to find patterns/rules where none have been formally published by the authority for a timezone.   Every/most years this causes airlines a hiccup for Tonga/Fiji.

e.g. Actual flight time Auckland to Tonga is 2hrs 50mins.  Up to November 5th, it is displayed as 2hrs 50mins.  But from November 5th this is calculated/displayed as just 1hr 50mins using IANA TZ info.

IATA who publish their own timezone updates to all IATA airlines based on authoritative communication from the governments concerned. IATA publishes that information as soon as announced, but IANA has not/does not until near the effective date unless some more important change forces a release.

Is the issue the release schedule?  It doesn't seem that way.  It seems the issue is lack of authoritative information.  Does IATA indeed have a source of authoritative information that isn't public?  Or do they do what IANA does in the absence of authoritative information, i.e., guess?  In other words, are we dealing simply with two different guesses that went in different directions?

If IATA does indeed have authoritative information, it would be great if they would share that information (the source material, not just the conclusions).

paul