Re: [LEAPSECS] new beginning

From: Poul-Henning Kamp <>
Date: Thu, 04 Aug 2005 10:13:31 +0200

In message <>, Steve Allen writes:
>On Thu 2005-08-04T09:27:20 +0200, Poul-Henning Kamp hath writ:
>> So one feasible option is to predetermine all leapseconds (or
>> leap minutes ?) for the next 50 years in advance.
>> That means an UT1-UTC difference that could go as high as 20-30
>> seconds but it is still locked and bounded (by our knowledge of
>> geophysics, admittedly, but bounded nontheless).
>This was one of the options presented by McCarthy around 1999 during
>the early ruminations about changing UTC. It was quickly excluded
>from the list of possible options, even before the Torino conference
>when Arias further discussed the predictive capabilities.
>It would be interesting to know why this option was excluded, but then
>it would be interesting to really know why any of this is happening.

That question I can answer conclusively:

The reason this is all happening is that far too many computing
devices and systems have been rolled out since 1999 without knowing
how and if they would deal with leap seconds, individually and on
the interfaces.

I belive the USA proposal tried to avoid any more leap seconds
happening, thereby saving a lot of contingency work primarily on
DoD systems.

Evidently that didn't work out the way they had hoped.

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.
Received on Thu Aug 04 2005 - 01:13:43 PDT

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