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From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: Re: Pending patches/issues before 0.9.15 release?
Date: Thu, 21 Nov 2013 23:54:41 +0100	[thread overview]
Message-ID: <20131121225440.GI1685@port70.net> (raw)
In-Reply-To: <528E5EB9.1080400@skarnet.org>

* Laurent Bercot <ska-dietlibc@skarnet.org> [2013-11-21 19:27:53 +0000]:
>  The short version of what right/ timezones are is explained here:
>  http://www.madore.org/~david/computers/unix-leap-seconds.html#tai-minus-10

according to the official tzdata code the "right/" directory
is obsolete and different path is used for this now

"The advantage of this scheme is that TAI−10 uniquely refers
to an instant in time, and the difference between two such
values determines the interval between these instants"

is not true, a single time coordinate cannot uniquely refer to
an instant in time (TAI only specifies the frame of reference
since 1977, before that it was largely nonsense and after that
it only measures the time somewhat accurately for observers at
sea level in rest, but eg outside the gravity well of earth it
is off by 22ms/year)

even in classical physics, a clock source with precise ticks is
not usable for representing dates because the rotation of the
earth is not exactly periodic (by which dates are defined)

so using the absolute time coordinate of an observational frame
of reference for date keeping seems to be rather futile

>  The difference between glibc and musl is 25 seconds, not 35 as I wrote,
> which seems to indicate that musl's gmtime()/localtime() does not take leap
> second tables, which are defined in right/ timezones, into account.
>  I would really love that to be fixed - maybe not for 0.9.15, but for 0.9.16
> if possible, because I'm a hardcore TAI-10 user.

knowing that TAI is non-conforming you need to provide a strong
use-case for it


  parent reply	other threads:[~2013-11-21 22:54 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-21  1:30 Rich Felker
2013-11-21  9:40 ` Laurent Bercot
2013-11-21 16:39   ` Rich Felker
2013-11-21 16:55     ` Szabolcs Nagy
2013-11-21 19:27     ` Laurent Bercot
2013-11-21 19:44       ` Rich Felker
2013-11-21 20:07         ` Daniel Cegiełka
2013-11-21 20:34           ` Rich Felker
2013-11-21 22:54             ` Laurent Bercot
2013-11-24 11:06         ` zoneinfo file parsing in __tz.c Laurent Bercot
2013-11-24 12:22           ` Szabolcs Nagy
2013-11-21 22:54       ` Szabolcs Nagy [this message]
2013-11-21 23:04         ` Pending patches/issues before 0.9.15 release? Laurent Bercot
2013-11-22  0:18           ` Szabolcs Nagy
2013-11-21 23:05         ` Rich Felker
2013-11-21 19:21 ` John Spencer
2013-11-23 22:02 ` Rich Felker

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