Re: [LEAPSECS] independence day

From: Markus Kuhn <>
Date: Wed, 05 Jul 2006 16:26:39 +0100

Poul-Henning Kamp wrote on 2006-07-05 05:49 UTC:
> In message <>, Steve Allen writes:
> >In the middle of May some text about legal time in the US was
> >introduced into a US Senate bill regarding funding for NSF and NIST.
> >See section 508 of S.2802 introduced 2006-05-15, e.g.
> >
> the term `Coordinated Universal Time' means the time scale
> maintained through the General Conference of Weights and
> Measures and interpreted or modified for the United States
> by the Secretary of Commerce.'.
> That could sound like the drilling of a loophole :-)

In comparison, the corresponding German law was phrased much more
cautiously. It ensures that any substantial tinkering with the
definition of UTC (and therefore German time) requires democratic
approval by parliament:

  Law on the definition of time (Zeitgesetz - ZeitG)

 "(3) Coordinated Universal Time is defined as a time scale with the
      following properties:

      1. On 1 January 1972, 0 hours, it corresponds to 31 December 1971,
         23 hours, 59 minutes, 59.96 seconds mean solar time on
         the null meridian.

      2. The scale unit is the base unit second according to section 3
         paragraph 4 of the law on units of measurement of 2 July 1969
         (BGBl. I, p. 709), last amended by article 287 number 48 of
         the law of 2 March 1974 (BGBl. I, p. 469), at sea level.

      3. The time scale Coordinated Universal Time is kept in alignment
         with mean solar time at the null meridian with a tolerance of
         not more than one second, either by inserting one additional
         second or by omitting one second."

In other words, the kind of minor optimizations of UTC that Rob Seaman
and others have proposed here (tinkering with the exact dates at which
leap seconds are scheduled and announced) would not require a change of
German law, but pretty much everything else discussed here (leap hours,
pure atomic time, etc.) does require legislative approval.

Sounds to me like the authors of the German Zeitgesetz of 1978 had
rather prudent advisors. Prudent members of the U.S. legislative branch
who are currently drafting revisions of the definition of U.S. national
time may want to have a close look at the above wording.


P.S.: The above English translation is mine; a HTML transcript of the official
German wording is at

Markus Kuhn, Computer Laboratory, University of Cambridge || CB3 0FD, Great Britain
Received on Wed Jul 05 2006 - 08:27:28 PDT

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