Hi Magnus,
On 2014-01-09 02:11 PM, Magnus Danielson wrote:
Hi Brooks,
Welcome to the list!
On 08/01/14 01:45, Brooks Harris wrote:
On 2014-01-07 03:40 PM, Poul-Henning Kamp wrote:
In message <52cc8c26.5090...@edlmax.com>, Brooks Harris writes:
I fully understand time zone specifications are fractured. My
objective
is to determine what standards are most relevant currently, that is,
what standards may be considered "in force". And where none exist, to
state some sort of rules of "common use" or "common practice" without
referring to the impossibly large collection of local jurisdictions
and
laws.
There is no way to do that, because timezones are purely a matter
under the jurisdiction of national or in some cases even provincial
governments, and they are free to do any damn thing they want to them.
Yes. What I'm trying to get at is - "Offset from UTC" seems pretty clear
- a given "+-xx:xx" gives you a hard-value to work with in the time
domain. But this doesn't seem to be clearly defined anywhere. I'm
looking for more than "because everybody does it that way".
Meantime, local jurisdictions choose to honor some locally defined "time
zone" including politically defined geographic areas. Time and position
are related but they are not the same. Typically, most elect to follow
"common use" precedent and choose a reasonable even-hour "offset from
UTC". (Yes, I know its sometimes referenced to GMT and other details
like that, and yes, Newfoundland and others are not on the hour.)
Various governments have repeatedly made sure this fact is not
overlooked.
I'm not sure I blame the governments quite so directly. As far as I can
tell both experts and officials are guessing what the "standards" of
"timezone" might be, so how can they be expected to conform to a
non-existent ideal? If someone is in charge of deciding the rules and
parameters of some time zone somewhere, what guidence do they have? And
the more you research it, the more confusing it becomes.
I think they mostly adapt to what is handy for trade. Keeping the same
clock as important neighbors to which they have lots of trade and
communication, that is in practice more important that aligning to the
15 degrees separations, even if that is a starting-point. The same
goes for the daylight-saving time. In Europe, the European Union
coordinated the daylight-saving time transitions to be at the same
time amongs members, as this avoids switching at different dates. This
however is not coordinated with the US, so I can have 8, 9 and 10
hours between me and California for example. It's also interesting to
note that this common document from 2001 have different types of
formulations depending on language, so GMT, meridian and UTC is used
alternatively depening on language, and if you want to be picky, you
don't know relative time between countries better than +/- 0.9 s.
So, it's a mess. It's not a technical problem, it just becomes one.
A) "International Date Line", which is probably not standardized
[...]
It is not.
In only exists as a the result of local governments deciding what
timezones to use.
Some Pacific Island nation "jumped" timezones for Y2K in order
to be the first country to "arrive in the new millenia.
The "intenational date line" is simply where you, in broad daylight,
have a country with one date on one side and another country with
a different date on the other side.
Yes. But its "roughly" 180 degrees from the "Greenwich meridian", as per
"International Meridian Conference of 1884" "Final Act III. "That from
this meridian longitude shall be counted in two directions up to 180
degrees, east longitude being plus and west longitude minus."
Its common practice that the jump to the designation of the next day
occurs at this "international date line", wherever the local authorities
may have chosen to place themselves, for examples UTC-offset +14:00,
+13:00, and +12:00. This topic, of jumping to the next day, is discussed
in many letters and common explanations, but I find no official
statement to that effect, even as a guideline.
B) The "International Meridian Conference of 1884" contains
significant
discussion of the idea "That these standard meridians should
continue to
be designated as even multiples of fifteen degrees from Greenwich",
but
there appears to be no explicit resolution of vote on the topic.
And there were none subsequently. Strict 15 degree meridians would
be very impractical, unless national borders were aligned with them.
Well, thats what even-hour UTC-offsets are, aren't they? And in
jurisdictions with even-hour UTC offsets, that's where they've placed
themselves in the timescale, right?
Despite significant attempts at map-redrawing in the first half of
the 19-hundredes, timezones were never a reason for it.
UTC was standardized so that telephone, telegraph and radio operators
would not have to keep track of local politics all over the world in
order to operate.
Right. And it almost works. It seems to me it could work better if the
loose ends of the underlying standards were better taken care of, hence
my interest in learning the current state of the definition of each of
these components.
In practice, the "olsen" database is a post-facto recording of
political whims with respect to timezones.
Again, "political whims" is really all they've got to go on. Maybe we
can do better?
Not without a lot of political whims. Simply put, just forget it,
won't happen.
It might improve, but the end game is way to far away.
Well, its clear the "end game" would take a long time to realize. It
will take serious patience on the part of folks who care.
My point is that the standards, where they exist, are dispersed and
fractured. This contributes to the confusion and proliferation of
non-interoperable systems. It must also contribute to "the political
whims" of any jurisdiction because of the lack of clarity. Any
government anywhere is faced with conflicting demands and internal
debate. Where any law concerning time-keeping is concerned it is very
difficult to understand the concepts and standards - its takes experts.
Its no wonder that the laws seem arbitrary because government
politicians are not likely to be time experts, the debate gets confused,
and they have more urgent topics on their agenda. They do the best they
can and move on.
So, an effort to simply consolidate the terms, definitions, and
standards into a single reference document would go a long way toward
lending clarity to system implementers, other industries, and,
importantly, to governments seeking to refine their laws to coordinate
time and commerce with other jurisdictions.
To be taken seriously enough to have an effect the document would need
to be developed by a credible, preferably international, due-process
standards body. Since this list is frequented by time experts from many
industries it seemed like a good place to float the idea. It might even
be a forum where an unofficial, experimental, document writing exercise
might take place.
So far, everyone has indicated its impossible, but I've been doing this
too long to give up the idea that easily.
Does anyone think the idea has any merit?
-Brooks
Cheers,
Magnus
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