[tz] Ethiopia local time

Tim Parenti tim at timtimeonline.com
Thu Oct 11 21:15:28 UTC 2018

On Thu, 11 Oct 2018 at 13:04, Steve Allen <sla at ucolick.org> wrote:

> On Thu 2018-10-11T12:12:21-0400 Tim Parenti hath writ:
> > On Thu, 11 Oct 2018 at 10:49, Paul Eggert <eggert at cs.ucla.edu> wrote:
> >
> > > To my mind this is more a localization preference than an independent
> time
> > > zone.
> >
> >
> > …which, again, is why I suggested specifying that tz starts numbering the
> > hours from midnight.
> "midnight" has no meaning at South Pole station, nor on the ISS, and
> very little meaning at McMurdo other than how tired the supply crews
> from Christchurch are likely to be.

That is a reasonable argument, though a bit imprecise.  "Solar midnight"
certainly has no meaning in those places, nor have I argued that it does.

> At those places the hour 00
> designates when the calendar day and date change.
> The concept of midnight is itself a localization of us temperate zone
> folks,

This is the more salient point, I think.  The folks in the places you
mentioned may (or may not) bring their more temperate cultural notions of
"midnight" with them to some extent, mainly with respect to communications
with home bases, but that's more "imported" than anything truly localized
to where they actually are.

See also: Tourists to the Arctic amazed to "see the sun up at midnight" in
the summer.  It seems to be an absurd statement on its face, but it's not
technically wrong, per se… at least, from their cultural frame-of-reference.

> and the word "midnight" has no place in tz other than in a
> footnote explaining the origin of the simplifications codified in the
> underlying tz model of time and date.

I suppose I could argue that the patch I originally proposed in
https://mm.icann.org/pipermail/tz/2018-October/026942.html *is* effectively
such a footnote (one that aims to limit tz's scope) — but an alternative,
more permissive, approach could certainly be taken to instead remove the
other main mention of "midnight" where instead "start/end of calendar day"
is more appropriate (likewise replacing "noon" with "midday").

Proposed alternate patch attached.  The general concept of "midnight" in
the wall-clock sense is, however, sufficiently commonly understood that it
need not be eradicated from the (highly localized) commentary throughout.

Tim Parenti
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