[LEAPSECS] Schedule for success

Zefram zefram at fysh.org
Tue Dec 30 06:57:45 EST 2008

Poul-Henning Kamp wrote:

>Did you also complain when the length of the meter was redefined ?

>wasnt that equally an insult to the users of the meter, who

>relied on it being a metal bar i Paris ?

Users of the metre don't rely on the form in which its definition
is expressed. They rely on its length being consistent. The various
redefinitions of the metre have all preserved its length, to the precision
measurable at the time.

The fact that UTC is a close approximation to UT is a visible feature on
which users can rely. We might be able to loosen the target bound on
DUT1 a bit (though that's a tricky business), but making it completely
unbounded would be a gross violation of the concept and visible behaviour.

The kind of places you're talking about that refer to "UTC" by name,
the ones that don't really need UTC, are the same kind of places that
refer to "GMT" by name and then actually use UTC. We've talked about
this kind of confusion quite a bit. In non-technical discourse, "UTC",
"GMT", and "UT" are effectively synonymous and all vague. So if TI is
defined by that name, we can expect that this pattern will continue:
"UTC", "GMT", "UT", and "TI" will (in those contexts) be effectively
synonymous, and even vaguer, covering all flavours of UT and also TI.
If, as you suggest, TI is defined but takes over the name "UTC", the
terms (in non-technical contexts) will still widen thus in meaning,
there'll just be one fewer term being used vaguely.

You can't fix this problem of incorrect nomenclature usage by changing
the meaning of one of the names. Please don't damage the nomenclature
for those who use it successfully.


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