[tz] Ethiopia local time

[Paul Eggert]

On 9/12/18 3:42 PM, Steven R. Loomis wrote:
> 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.

That makes sense. It's a clearer way to address the issue, and I do see 
the resemblance to the issue of Japanese times that go past 24:00.

My understanding, by the way, is that it's not as simple as saying that 
06:00 western time is equivalent to 00:00 Ethiopian time the same day, 
and that Western and Ethiopian clocks tick at the same rate. Although 
that is common practice in business in the major cities (and no doubt 
cell phones have a lot to do with this), it's an approximation of a 
tradition that is also mentioned in Mortada's PRI story, which is that 
each day and night is divided into 12 equal hours, and that summer days 
and winter nights have longer hours. Ethiopia is close enough to the 
equator that the modern business approximation is reasonably close, but 
it is just an approximation. Before cell phones became ubiquitous, as I 
undertand it, people set their watches to 12 o'clock at dawn: although 
this is a better approximation to tradition than the simpler "subtract 6 
hours" method used with cell phones, it's still just an approximation.

Just to make things more interesting, I've also been told that some 
people in Ethiopia set their watches to 6 o'clock at dawn, which would 
be yet another compromise between traditional and Western timekeeping. 
Sorry, I don't know the details about this (e.g., is it done only in 
some regions, or is it more an ethnic-group thing?).

If you have a cell phone, there are apps that will display Ethiopian 
business time, and to some extent these can fill in for CLDR and/or 
tzdb. I don't know if these apps agree about the timekeeping details, 
though (such as exactly when the date ticks over). See:

https://play.google.com/store/apps/details?id=com.addistag.time

https://itunes.apple.com/us/app/ethiopia-time-ethiopian-12-hour-clock/id793947294