[tz] EU Public Consultation on summertime arrangements

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Mon Jul 9 15:00:27 UTC 2018

On 2018-07-09 01:25, John Wilcock wrote:
> I'm surprised a consultation by the EU hasn't provoked more comment here. Anyway...

It still comes down to each country's ministers, government politicians, or
parliamentary members deciding or voting on which UTC offset to follow.

Nothing anyone on this group can do to influence those decisions, except
encourage them to provide sufficient advance notice that give large software
vendors, like MS, RedHat, Oracle, Apple, Google, and their OEMs and carriers, a
sufficient number of months to push changes thru their implementation, QA, and
release processes at their normal, glacial pace.

Most Android phones (or tablets) over a couple of years old will no longer be
getting any updates, unless the EU adds directives mandating changes be pushed
to older devices.

If DST is abolished, the tzdb common EU rule gets changed to terminate DST
changes as of the change date.

If a country changes its UTC offset, the tzdb entry for the reference city in
that zone gets updated with the change date and changed UTC offset.

This will be similar to the 2007 North American change where the tzdb common US
and Canada rules were updated with the new switch dates criteria, and each time
zone's entry changed, if required, as each state, province, regional, or
national government made official announcements available on the web.

It would be helpful for everyone if the EU tracked all these legislative time
zone changes, including links, in a common document, possibly appending
membership candidates, potential candidates, Schengen area, and other European
countries not in the EU, who have decided to make a concurrent related change.

> I'm not entirely convinced your second point is clear enough for bureaucrats not
> familiar with all the underlying concepts to understand.

>> [...] if the European Union elected to go to permanent daylight saving,
>> there's a good chance the Time Zone Database would model it as permanent
>> standard time: for example, it would model permanent Central European
>> Summer Time (CEST, UTC +02) not as daylight saving time, but as either
>> permanent Eastern European Time (EET, UTC +02), or as a standard time whose
>> name happened to end "Summer Time".

> Surely tz could/would simply define new Western, Central and Eastern European
> Standard Time zones and assign the relevant locations to them as from the
> transition date, rather than "model" them to existing zones? Or are you
> suggesting that systems that aren't properly updated would present misleading
> names to users?

WET, CET, EET, and related summer time zones have defined meanings, and are also
used by other non-EU countries, who may continue to observe DST or not. It would
make no sense to change names which are understood, to have different meanings,
depending on whether a country had EU membership.

>> Although this may seem like a small point as the UTC offsets of CEST and
>> EET are identical, having multiple names for the same permanent time
>> zone would undoubtedly confuse users and operators of computers, cell
>> phones, and the like. For this reason, if the twice-yearly clock change
>> is abolished, the EU should simply move time zone boundaries rather than
>> proclaim "permanent summer time" in some areas.

> It occurs to me that the EU might well decide to leave the boundaries as they
> are, and merely change the UTC offsets. How about "To minimise potential
> confusion, the EU should simply proclaim new UTC offsets for the 'standard time'
> in each zone and, if applicable, define any changes in zone boundaries"?

Each country will decide on its own UTC offset, and any changes will be applied
to the time zone named after the reference city, so the "zone boundaries" will
be implied by the offsets observed by the residents of the regions.

Andorra, Moldova, Monaco, San Marino, Switzerland, and the Vatican may decide to
follow the adjacent regions or may differ about changes and/or summer time.

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

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