[tz] Ethiopia local time

Tim Parenti tim at timtimeonline.com
Wed Oct 10 02:48:02 UTC 2018

That's not really a coherent argument against the proposal.

It *can* mean that — and of course once did, approximately — but anymore,
it generally doesn't, and there's little correlation between the two.
Where I live, at this time of year, "solar midnight" is approximately 01:07
local time, but if I just say "midnight" to any of my friends or
colleagues, they know unambiguously that I'm referring to the time-of-day
when the wall clocks say 00:00, regardless of where the sun might be at
that time.  (Although, in any given social context, it might more
accurately refer to 24:00 on a *particular* day, that's ultimately just the
same time-of-day expressed differently.)  There would no confusion that I
might mean "solar midnight" or even "standard midnight" unless I were in
very particular technical settings.

I'm not sure how the Ethiopian words for "midnight" and "noon" translate,
but the fact that they would number those both as 6 (in a 12-hour system)
is what the extra specificity is trying to communicate is (presently)
out-of-scope: tz effectively "counts" from 00 at midnight (not considering
DST changes), and we already state as much elsewhere.

Tim Parenti

On Sat, 6 Oct 2018 at 04:09, Phake Nick <c933103 at gmail.com> wrote:

> Wait a moment, I thought the term "midnight" usually refer to middle of
> the night instead of the 00 hours?
> 2018-10-6 06:52,Tim Parenti <tim at timtimeonline.com> wrote:
>> Sure, but the notion of "wall-clock midnight" under year-round +6 DST is
>> no more or less tied to actual solar midnight than for any other zone as
>> they exist today.  As Steve puts it, hour 00 just represents the hour at
>> which the calendar date changes.
>> In your extreme example, it may seem odd to say it's midnight when the
>> sun is still setting — and I'm certainly not suggesting Ethiopians would
>> actually do anything remotely similar  But these discrepancies don't stop
>> folks from referring to 00:00 local time as "midnight" in most of the cases
>> we cover, even if it… well… isn't.
>> Moreover, we already make explicit this convention (tying hour 00 to the
>> Western cultural notion of "midnight") elsewhere:
>> https://github.com/eggert/tz/blob/b709eb84eaa48354186d4a11c86395e399f19c12/zic.8#L281-L282
>> Again, I won't be bothered if it's left out, but I also haven't really
>> seen any reason against such a clarification.  Perhaps my proposed wording
>> is not the best.
>> --
>> Tim Parenti
>> On Thu, 4 Oct 2018 at 23:49, Phake Nick <c933103 at gmail.com> wrote:
>>> That's not really the case. If some country decided to actually
>>> implement a year-round +6 DST, then that would also be included in tz
>>> database
>>>  2018-10-5 07:48, Tim Parenti <tim at timtimeonline.com> wrote:
>>>> For tz's purposes, though (the sentence begins "The tz database models
>>>> time using…"), those are synonymous.  Of course, this may not be the case
>>>> if you're using a workaround like the one suggested for Ethiopia, but the
>>>> goal is to further clarify that that's out of our scope.
>>>> --
>>>> Tim Parenti
>>>> On Thu, 4 Oct 2018 at 19:14, Steve Allen <sla at ucolick.org> wrote:
>>>>> On Thu 2018-10-04T18:13:56-0400 Tim Parenti hath writ:
>>>>> > To bring this back, then, to a recognition of the potential
>>>>> differences in
>>>>> > how the hours are counted, we should probably expand the text in
>>>>> theory
>>>>> > slightly to specify that tz counts hours under the assumption that 00
>>>>> > represents midnight.
>>>>> I think that 00 represents the hour at which the calendar day and date
>>>>> change.  That may not happen in the middle of the night.
>>>>> --
>>>>> Steve Allen                    <sla at ucolick.org>              WGS-84
>>>>> (GPS)
>>>>> UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat
>>>>> +36.99855
>>>>> 1156 High Street               Voice: +1 831 459 3046         Lng
>>>>> -122.06015
>>>>> Santa Cruz, CA 95064           http://www.ucolick.org/~sla/   Hgt
>>>>> +250 m
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