[time-nuts] UTC

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Jul 25 16:09:10 EDT 2005

In message <75DA592E-7563-4B0C-A418-4148590A7EAF at noao.edu>, Rob Seaman writes:
>Poul-Henning Kamp says:

>That said, are you of the opinion that your limited perception of my  
>project list (or social calendar, for that matter) has anything at  
>all to do with resolving technical issues?

No, I'm saying that you thinking it is a technical issue is pretty
much the central problem in our discussion.

This is a political issue because the economics of following
the "obvious technical solution" are prohibitive.

>1) Civil time is a subdivision of the calendar and is thus a  
>representation of time-of-day.

The almost universal adoption of timezones and daylight savings
time disproves this definition:  Civil time varies up to 30
degrees or two hours from "time-of-day" in many areas of the

>2) That said, one could imagine basing civil time on some time scale  
>other than UTC.

Yes, one could conceiveably imagine that.

But only if one ignores the the astronomical cost of converting all
the documents, manuals, directives, schedules, agreements, contracts,
trading rules, flight schedules, (just to mention some) of the
places that now have text that refer to UTC.

For people who are aware of this cost, it is immediately obvious
that saying "Make your own damn timescale" to the astronomers is
so many orders of magnitude cheaper, that such a proposal will never
be taken serious in intelligent debate.

>This is a policy question that should be addressed  
>forthrightly, not via a tricky initiative involving a mid-level  
>bureaucratic committee.

I can guarantee you that it has been addressed definitively
in my statement above.  You will not ever get another decision

>We aren't just talking about leap seconds,  
>we are talking about the definition of the concept of the "day".   

No, we are not.

A day is defined as 24 hours and the fact that some of them are
24h1s is in violation of countless laws and regulations throughout
the world.

>This is a potentially explosive political, legal and religious  
>issue.  Its current obscurity should not be taken for granted.

Right, and we don't: we're trying to get rid of the 24h1s obscurity.

>3) Whatever time scale civil time is based upon, the integrity of the  
>underlying time scale should be respected.  UTC has an existence  
>separate from the ITU.  It should be maintained whether or not civil  
>time continues to correspond to UTC.

If anybody put their eggs in the UTC basket and didn't realize
that ITU carried it, they have only themselves to blame.

>The current proposal is as much an attempt to sweep this  
>important work under the rug, as it is an attempt to avoid subjecting  
>non-conforming systems to the horrors of leap seconds.  Shame on  
>anyone who is looking for an easy way out.


When cost estimates start running into the billions of dollars,
looking for an easy way out is not optional any more, then it
becomes a duty.

And saving even a few tens of millions of dollars can never be
a shamefull thing for anybody.

>Time is complex.  Embrace the complexity.

No, geology and orbital mechanics is complex.

Time is just as simple as any other fundamental measurement unit
like the meter, the kilogram or the volt.

Once you stop confusing geophysics with time, then we will be
able to discuss this rationally.  As long as you confuse the
two, we get nowhere.

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.

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