[LEAPSECS] LEAPSECS Digest, Vol 45, Issue 1
M. Warner Losh
imp at bsdimp.com
Thu Sep 2 15:45:33 EDT 2010
In message: <722F0D89-CBFA-423A-9C9E-6D919DED9C4D at batten.eu.org>
Ian Batten <igb at batten.eu.org> writes:
: > I'd wager that UTC, whatever its realization, would likely trump any
: > locally written laws.
: It'll be interesting in the UK
: * There's no doubt that UK legal time is GMT, Interpretation Act 1978,
: * S.9
: * There's no doubt that whatever GMT is, it's solar, and there's no
: * doubt that whatever UTC is, it isn't solar and would be even less
: * solar without leap seconds,
: * There's no doubt that proposed legislation to change UK legal time to
: * UTC failed to be passed in 1997, and an extensive history of the issue
: * got read into Hansard.
: You'd have a hell of a job showing UK time was UTC in the face of
Do you have references to case law that confirms this interpretation?
Citing a literal reading of the current law doesn't prove that the
text is the actual law, as interpreted by courts. There are many
instances in this country where the literal meaning of the law was
interpreted by courts to be more liberal or restricted than the law as
The national labs that are keepers of the official time have been
publishing UTC. I'd t is the de facto standard that everybody is using.
Based on that, I suspect someone will make the case that the official
time is what people can access as the official time, as opposed to
some theoretical time that is extremely difficult to access today.
: > After all, UTC has been a widely accepted
: > approximation of the local laws that's attained the force of law
: > through repetitive use
: That's right, but |DUT1|<1 means that for the purposes of integer
: arithmetic it's barely more than a rounding error. There's clear,
: modern legislation to the contrary.
Interesting, but not likely relevant. UTC is a published time
everybody can agree on. The technicalities of the legislation may not
be relevant if nobody follows them.
: > (how many real-time realizations of UT1 are
: > propagated, in comparison to UTC). So underlying technical changes to
: > UTC may not change that. It would take a long, and complicated, legal
: > argument to show that UT1 is what should be used
: Not in the UK, see above.
The above lacks case law confirmation. Sure, it is what the law says,
but that isn't that what it really means. Seriously, when the judge
has to choose between a time that people can obtain, and a theoretical
one that most people don't have access to, I believe that actual
practice will trump theory. These sort of minor corrections to the
law, as written, happen all the time. It is impossible for someone
today to say, with absolute certainty, what the legal rulings will be
in the future. My options here are just that: my guess at the likely
: > (even though nobody
: > knows what it is, day to day).
: That's the paradox, isn't it!
Right, but it leads to a legally untenable position. A law that
nobody has the practical means of complying with is unenforceable, and
is likely to be adjusted by court rulings to be an law that people can
Even before the US officially switched from mean solar time to utc,
the us law wasn't mean solar time. It was mean solar time as
interpreted by the secretary of commerce, which had for years been
interpreting mean solar time to mean UTC... Nobody was propagating
anything except UTC... The law said mean solar time, true, but
everybody was using and recognizing UTC since that's what NIST was
telling everybody was the official time. I don't think this was ever
legally tested, however.
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