[LEAPSECS] The relation between calendars and leap seconds.

[Rob Seaman]

Poul-Henning Kamp wrote:


> The POSIX and FIPS-151-2 requirement is that you use UTC (with 86400

> seconds per day), they doesn't say how good you have to be at it.

>

> In other words: if you set your hourglass after your WWVB alarm

> clock, and turn it over as required, all the way in the subway to

> work, and then set the clock on www.cia.gov from it, then you are

> in compliance.


Hmmm.  Forget about the details of the two main positions historically  
prevalent on this list.  Call them position "A" and position "B",  
rather than "leap seconds must die!" and "friend of mean solar time",  
respectively.

It occurs to me that I may not actually understand the underlying  
motivation for someone to hold position "A".  (We've been over and  
over the motivations behind position "B".)

I thought the motivation for holding position "A", was something like  
"commercial entities, especially those beholden to POSIX, throw a  
tizzy at each leap second".  I'm not here to debate the  
appropriateness of this motivation.  Rather, just - is this actually  
(more or less) it?

Because what you are saying here is the converse of that statement.   
The description above is not of commercial and personal systems that  
need highly regular time signals without interruption to intervening  
intervals.  The description above is simply of bending over backward  
to match some broken regulatory ("non-functional") requirement, no  
matter how irregular the timescale has to be.

Wouldn't time be better spent correcting the requirement?


> If you set up a high quality radio-clock which steers your personal

> office workstation in the Bureau of Tobacco, Arms & Alcohol to

> within 1 microsecond of Robs "TI" timescale, then you are non- 

> compliant,

> *even* if TI == UTC at that point in time.


Here's another of those strawman positions, set up just to be  
rhetorically knocked down.

It isn't my TI, of course, but rather the consensus of the only public  
meeting held on the topic.  I didn't attend that meeting.  In any  
event, I would have argued for some different name if nothing else.   
We're likely to be sued by the company that makes Beanie Babies :-)


> On the other hand, the Sarbanne-Oxley legislation had a lot of

> $BIGCORP scrambling for timesynch of their systems because their

> lawyers interpreted it to have an implicit requirement for  

> traceability

> to UTC time on all "relevant" computers.


System design by lawyer.  There's a recipe for success!

Rob Seaman
NOAO