[tz] looking for information about changing time zone

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Tue Sep 8 17:23:08 UTC 2020

On 2020-09-07 15:50, Françoise Kerjouan via tz wrote:
> Madam, Sir,
> I’m living in New Caledonia; our local government is thinking about changing
> time zone (from UTC +11 to UTC +12).
> Could you please tell me how long a lead notice should be to be sure that the
> international community will get and process the information ?
> I understood that the ICAN TZ database is widely used, but I didn’t catch if it
> is also used for international transports (by airports for example). Could you
> please tell me if it is the case? If not, whom should I ask for?

Your airports serving regular scheduled flights, the airlines servicing them,
and your air service regulators, are responsible for informing IATA of various
changes affecting local times of schedules, with the contracted notice for IATA
to update their master schedules, and update subscribers by issuing updated IATA
SSIM Standard Schedules Information Manual:

As NC is a TOM of France governed by the DGOM, they may have control over time
changes and those responsibilities may be theirs.

For all other purposes, from clocks and mobile phones to almost all larger
computer systems, providing all the same details here with a few months notice,
will allow time for the global time zone data base maintainers here, and
downstream major and minor systems and product providers, to make, test, and
deploy changes, that will allow personal and small to enterprise systems,
databases, and other products (like mobile, desktop, and enterprise calendar and
scheduling programs) to properly handle the time change when it occurs.
This will facilitate people making it onto their (possibly rescheduled) flights.

If governments could let this mailing list know as soon as possible of any
changes, there would be many fewer disruptions to their citizens lives and
schedules, and those who communicate with them.

Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in IEC units and prefixes, physical quantities in SI.]

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