Klarinet Archive - Posting 000630.txt from 1998/08

From: "Mark Charette" <charette@-----.org>
Subj: Re: [kl] Re: Y2K
Date: Fri, 21 Aug 1998 18:09:44 -0400

-----Original Message-----
From: Tim Roberts <timr@-----.com>
> That is, until 2099, when we'll do it all again, because
>programmers in 2069 won't remember the great "Y2K" issue, and will be
once
>again storing only the last two digits.

Actually - I think the next date will be sometime in 2038 for all the
obsolete 32 bit machines which count seconds in a 32 bit integer. Since
64 bit machine are available now, the computers using 32 bits for
counting seconds in 2038 will be _real_ obsolete.

For a moderately funny Y2K story:
I've done a bit of work recently for some airlines. There ended up being
one piece of equipment that did some "interesting" things when the year
2000 hit. The Inertial Guidance System on the jets decides that
something is wrong at exactly that time and resets itself, making the
plane try to fly to Greenwich, England if the autopilot is on. A reboot
of the IGS a second after the epoch will fix the problem.

Yes ... they've already flown the planes simulating Y2K, and that was
the only serious issue. There's a minor one in the readouts on some of
the equipment because of a glitch in computing the number of days in
February, 2000.

>From the Astronomy FAQ:

"The rule for leap years under the Gregorian calendar is that all years
divisible by four are leap years EXCEPT century years NOT divisible by
400. Thus 1700, 1800, and 1900 were not leap years, while 2000 will be
one. This rule gives 97 leap years in 400 years or a mean year length
of exactly 365.2425 days.

The error in the Gregorian calendar will build up to a full day in
roughly 3000 years, by which time another reform will be necessary.
Various schemes have been proposed, some taking account of the changing
lengths of the day and/or the tropical year, but none has been
internationally recognized. Leaving a reform to our descendants seems
reasonable, since there is no obvious need to make a correction now."

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