[LEAPSECS] The relation between calendars and leap seconds.

Poul-Henning Kamp phk at phk.freebsd.dk
Tue Nov 11 13:53:14 EST 2008

In message <20081111180003.GA26971 at ucolick.org>, Steve Allen writes:

>But Denmark performed an interesting substitution



>Whereas I'll admit this is likely one aspect of limited human

>cognition -- the failure to recognize a significant difference

>between UTC and GMT, with effort it could be interpreted to

>say that Denmark expects that UTC and GMT will remain


We're talking about the country where legal time is mean solar time
of 15E, but DST is defined relative to GMT, what level of correctness
do you expect the state department give a south-american countrys
press-announcements about something as booring as time ?

>But there are lots of examples of systems which try to assign meaning

>to proleptic UTC, proleptic POSIX time, MS Windows time, .NET time, etc.

>Proleptic interpretation of UTC is horribly broken with lots of

>disagreeing algorithms even only for the late 20th century.


>One of the best ways to limit the kinds of mistakes that limited

>human cognition makes is to put the toys out of their reach.

I don't think you can avoid this on any civil timescale, the average
journalist cannot resist calculating "that Alexander The Great
died on a Thursday" if they are out of intelligent reporting to do.

>I still assert that the safest means of going forward is for ITU-R to

>wash their hands of UTC and say


> We don't care what you do with UTC, and we can't get the rest of

> the world to agree on whether or not UTC should change.[...]

This doesn't solve any problems for anybody.

Since computers (mostly, se Denmark above) run on legal time, and
legal time is linked to UTC, then it certainly does not solve the
issue of computers not coping with leap seconds.

It adds a timescale, but we have plenty of those already, only
I can't see anybody using this one for anything

And that is the crux of the matter: The millions of computers in
the world are stuck with UTC, until such time as all the governments
enact laws that says otherwise.

Any relief from the leap second madness therefor has to happen
on the UTC timescale to have any effect.


Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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