Re: [LEAPSECS] Mechanism to provide tai-utc.dat locally

From: Poul-Henning Kamp <>
Date: Thu, 28 Dec 2006 21:28:04 +0000

In message <32100E59-869D-46E8-AA81-309C913E0FDF_at_NOAO.EDU>, Rob Seaman writes:
>M. Warner Losh wrote:
>> And avoiding the ugly 61 or 59 second minutes to define away the
>> problem...
>It was the time lords who decreed that rubber minutes were prettier
>than rubber seconds. We're now to skip right over rubber hours to
>rubber days? Their aesthetic sense seems strangely malleable.

It is not an ęsthetic issue, it is an issue of practical implementation.

In days no more than 100 clocks worldwide were precise enough to
care about rubber seconds, they were acceptable.

In days where no more than 1000 clocks worldwide were seriously
affected by leap seconds, they were acceptable.

In these days of heavily computerized infrastructure, we need more
than half a years warning about discontinuities in the timescale.

We can get that only by increasing the DUT tolerance.

As Warner, I and others have repeatedly emphasized: It is not the
step size that is the problem, it is the 6 month warning.

I don't care if you want to implement leap-milliseconds, as long
as you tell me 10 years in advance when they happen.

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 Dec 28 2006 - 13:38:48 PST

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