[time-nuts] Re: UTC

Poul-Henning Kamp phk at phk.freebsd.dk
Thu Jul 28 02:24:57 EDT 2005


In message <42E813E4.4090001 at erols.com>, Chuck Harris writes:

>> Just because people don't care or notice, doesn't mean not important
>> to them.
>> 
>> Most people don't care about water, sewers, electricity and civil
>> order.  That doesn't mean it's not important to them.  They care
>> a lot as soon as it doesn't work.
>
>Certainly.  But what's your point? 

It's just above in the first sentence:  Just because your neighbor
hasn't heard about leap seconds doesn't mean that they are not
important to him.

>> No, your position is diffrent from Robs, you just don't recognize
>> the potential for harm at all, Rob at least recognizes that.
>
>You may think that, but you would be wrong.  I see things differently
>than you.    I don't see a world where the truly critical systems need
>to be synced to UTC.  Like all of the foibles engineers make, if time is
>truly critical to an application, then the application will contain its own
>timekeeping, and perhaps its own timescale.  (Think NASA and mission
>time. ) TAI was developed to handle those cases where seconds needed
>to be handled in an unambiguous way.

That's a nice point of view, but experience seems to indicate that you
have not been able to sell it much.  Practically anything I see these
days stipulate UTC time.

>> Until after a leap-second hands in the unbudgeted expense or if
>> we are lucky: the budget request.
>
>You won't see any such budget request.  None happened 7 years ago,
>and none will happen this time either.

Have you seriously contemplated the difference between the systems
which were deployed 7 years ago and those deployed today ?

>The time functions where leap seconds
>matter will simply get another line added to their tables of anomalies.  The
>time functions where leap-seconds don't matter (most), will march along as
>if nothing happened.

And someplaces those two kind of systems meet and trouble ensues...

Because unlike your ideal world, in the real world people slap computer
systems up without thinking about time.

-- 
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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