[tz] Ethiopia local time

admin at afocha.com admin at afocha.com
Wed Sep 12 21:05:15 UTC 2018


Greetings everyone, 

Thanks for the replies! The time is not adjusted for the exact sunrise
of each day, but rather consistently applied as -6:00 on East Africa
Standard Time.  In the context of Ethiopia, this adjustment is widely
used in business and government activities.  People will use the EAT
time when speaking to someone they see as a foreigner, but if you live
in the country for some time, you are expected to internalize this
time system.  Incorporating this as a formal time zone would allow
for the local norm for telling time to be modernized.

Given that it is a static shift and not based on actual sunrise, what
is the barrier to legitimizing this as a formal time zone? What would
be considered an authoritative basis for incorporating this as a time
zone? 

Another person on the mailing list replied to me noting that the same
type of adjustment is often used in Kenya, which is also in the same
time zone as Ethiopia.  I will check with my contacts in Sudan and
Somalia and see if the same convention applies in those places.

Regards,
Khalid

----- Original Message -----
From:
 "Patrice Scattolin" <patrice.scattolin at oracle.com>

To:
<tz at iana.org>
Cc:

Sent:
Wed, 12 Sep 2018 16:23:36 -0400
Subject:
Re: [tz] Ethiopia local time

 Keep in mind that if 'local convention' is 6:00am is synchronized to
sunrise then the time changes every day since sunrise time is
different every day (usually by about a minute or 2 but that depends
of the time of the year). That would have the consequence that every
day could be slightly longer or shorter than 24h and that DST shift
would occur every day.  More over the time of DST shift would be
variable since sunrise is.

 And if we care to be accurate to the millisecond, you need to know
the actual longitude since that time variation of sunrise is a
continuous phenomena and therefore the time of shift of DST in the
east of the country would be different than the one in the west of the
country with respect to UT for any given day. 

On 12/09/2018 4:05 PM, Paul.Koning at dell.com [1] wrote:

 What does the TZ database mean "local time" to be? Time in its common
representation where zero is midnight and 12 o'clock is noon? Or is it
meant to account also for local conventions that zero is some point in
the day different from midnight?

 If the former, then this issue is out of scope. If the latter, then
it suggests there might be two Ethiopia zones, one for "midnight
origin" (the one we have now) and one for "local convention" which
combines the offsets from latitude, and the offset from the different
convention of what the starting point is.

 paul

-- 

 Patrice Scattolin | Software Development Manager | 514.905.8744
Oracle Cloud

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 Suite 1900
 Montreal, Quebec 



Links:
------
[1] mailto:Paul.Koning at dell.com

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