Re: [LEAPSECS] rubber time

From: Poul-Henning Kamp <>
Date: Fri, 05 Aug 2005 19:58:57 +0200

In message <>, Rob Seaman writes:

>It is fact, not fiction, that there are 86400 seconds per solar day.
>It is also a fact that a second has a precise SI definition. Which
>is more real?


I agree fully: at some point a bad decision mixed fundamental unit
(SI second) and geophysics (solar time) and as has been chronicled
already, some of the ingredients were even past their "sell by"
date when the mixing was done.

The computer guys, even though being too late to the main party
managed to screw things up even more by totally ignoring leap seconds
in what was mindlessly turned into the POSIX standard which is now
a holy text which cannot be changed until the second coming of
Dennis, Ken & Brian.

(This is where we look accusingly on each other and utter "What
another fine mess you got me into!" :-)

>The obvious definition as a fraction of a solar day -
>rubber seconds and all? Or the obscure definition that I challenge
>anybody to recite without aid from the Chemical Rubber Company?

(This is probably not the correct company to throw that challenge, quite
a few of us have cesium standards in our basements and we're quite
proud of them, so we happen to know the definition :-)

I know you hate this answer, but technology has made the decision
for us already.

Atomic clocks, now approaching 1cm^3, will gradually be used more
and more places, and that will mean that civil time will be linked
harder and harder to the SI-second. That leaves only counting
as viable adjustment.

For the counting to work, the computers need to know how to count
and when to count.

For that to work, six months notice is just not enough.

How about giving 50 years advance notice of leapseconds ?

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 Fri Aug 05 2005 - 10:59:10 PDT

This archive was generated by hypermail 2.3.0 : Sat Sep 04 2010 - 09:44:55 PDT