[LEAPSECS] Schedule for success

blb8 at po.cwru.edu blb8 at po.cwru.edu
Tue Dec 30 15:41:31 EST 2008

> Date: Tue, 30 Dec 2008 12:11:35 +0000

> From: Poul-Henning Kamp <phk at phk.freebsd.dk>

Greetings one and all. I didn't know this list existed until recently, have been reading the archives, and probably have little substantive to add. It is interesting to note that the arguments have changed little over the years (as far as I can tell from the archives).

> In message <20081230115745.GR2263 at fysh.org>, Zefram writes:


> >The fact that UTC is a close approximation to UT is a visible feature on

> >which users can rely.


> The crucial question, which nobody seems to be able to give an example

> of, is users who _DO_ rely on this being the case, and if any such

> users do exist, what their DUT1 tolerance is.

I thought astronomy was the first easy example of this. If we have any IT concerns about functioning backup systems, then I would think the importance of something useable in the absence of a GPS signal would be important too.

> >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.


> A lot of these places use UTC (or GMT) because of laws, regulations,

> standards and requirement documents.


> We can argue until the cows come home, if that constitutes a "valid

> need for UTC" seem from a scientific point of view, but that would

> not change their legal need one iota.

I certainly have no data to dispute Poul-Henning here regarding how ATC functions and the like, but one question that I haven't seen answered: Why do they use UTC is this problem is known? As I understand it, we're talking about something that is internationally controlled, meaning that the ATC system, for example, _chose_ to use UTC, with the knowledge that it had leap seconds. They same can be said for all of these laws and regulations. They chose to use something with leap seconds. Am I completely wrong here?

It seems strange to me that a locality could embrace something via its laws and then complain for failure to read the documentation. I think that's some measure of embrace and destroy.

Brian Blackmore
blb8 at po.cwru.edu
PGP keys not at http://cheese.cwru.edu/PGP/PGP.html
(ask me for them)

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