[tz] Ethiopia local time

[Steven R. Loomis]

Sure, off the top of my head:

 • Time zone is often associated with a specific user in a particular
location. multiple *calendar* systems are commonly shown in parallel within
one UI, sometimes within the same string.  For devices (say a desktop or
mobile computer, or a physical clock) there is usually a single setting for
time zone.  All of this to say, that the 'western' and 'ethiopian' [1]
systems should be shown side by side, on a single device that currently
would only have a single time zone.

• As opposed to the division AM/PM, there are time periods that need to be
used ( see https://unicode.org/cldr/trac/ticket/8473 ) such as "ከሰዓት -
afternoon - 6:01 to 11:59 Ethiopic = 12:01 to 17:59 Gregorian"  which need
to be calculated based on local timezone-adjusted time. If the time zone
were skewed by 6 hours then the period would be off.

• It also wasn't clear if the day-of-month boundary would necessary follow
the adjusted time. A 'simple' TZ offset doesn't allow this flexibility.

• there are other hour cycle systems (day start at sunset, astronomical
julian day start at noon etc) and so more flexibility is needed in general.

• for software use, our APIs  (ICU) return timezone information separate
from time of day calculation.

I know that wearing a watch upside-down is done in some places, but this
may also not be optimal.

Hope this helps,
Steven

- [1] we definitely need better terms here— this system is certainly used
outside of ethiopia. I use the term 'western' because that is what I have
seen used contrastively with the 'ethiopian' system.

On Wed, Sep 12, 2018 at 3:46 PM Khalid H. Duri <zewari at gmail.com> wrote:

> Hi Steven, can you expand on some of the problems that can be
> anticipated with using UTC-3?
> On Wed, Sep 12, 2018 at 3:43 PM Steven R. Loomis <srl at icu-project.org>
> wrote:
> >
> > For what it's worth, CLDR is tracking this issue at
> https://unicode.org/cldr/trac/ticket/9716 — my current thinking is to
> have something called a "time cycle", but it would be applied on top of the
> time zone calculation. Supporting it if it were  UTC-3 has other problems.
> >
> > I think it should be considered a localization and not a time zone issue.
> >
> > Steven
> >
> > On Wed, Sep 12, 2018 at 3:14 PM David Patte <dpatte at relativedata.com>
> wrote:
> >>
> >> But if you ask them in English, they say '12 o'clock'. If they wear a
> >> watch, it uses 'English time', and is set with midnight/noon at twelve.
> >> But they subtract 6 from 'English time' time when speaking Swahili and
> >> their own tribal languages.
> >>
> >>
> >> On 2018-09-12 18:03, David Patte wrote:
> >> > The system is also used in Kenya, Ethiopia's neighbour. If you ask
> >> > anyone in Swahili what time lunch is, they say 'six o'clock'.
> >> >
> >> >
> >> > On 2018-09-12 17:41, Steve Allen wrote:
> >> >> On Wed 2018-09-12T16:58:39-0400 Arthur David Olson hath writ:
> >> >>> Per the "Theory" file: "...the world is partitioned into regions
> whose
> >> >>> clocks all agree..."
> >> >>> So at least at the moment, the goal is to reflect what clocks say
> >> >>> the time
> >> >>> is rather than what people say the time is.
> >> >>> That goal is, of course, subject to change.
> >> >> It would be useful to know if privately set clocks and wristwatches
> >> >> commonly use this 6 hour offset.  If that is the case then it seems
> that
> >> >> Ethiopia is much the same as Asia/Urumqi
> >> >>
> >> >> --
> >> >> 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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