Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site lanl.ARPA
Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!genrad!panda!talcott!harvard!seismo!cmcl2!lanl!jlg
From: jlg@lanl.ARPA
Newsgroups: net.puzzle
Subject: Re: Computer bugs and the year 2000
Message-ID: <20268@lanl.ARPA>
Date: Fri, 25-Jan-85 14:35:32 EST
Article-I.D.: lanl.20268
Posted: Fri Jan 25 14:35:32 1985
Date-Received: Wed, 30-Jan-85 05:18:04 EST
References: <304@decwrl.UUCP>
Sender: newsreader@lanl.ARPA
Organization: Los Alamos National Laboratory
Lines: 21

> <>
> 
> I have heard that some software take into the account that the year 2000
> is a leap year when indeed it is NOT a leap year.  The computers can
> roll over to that year, but will be off by one day after February 28th...

But 2000 AD IS a leap year!  It's divisible by 400.  The rule is:

leap year every four years (year number divisible by 4)
except every 100 years (year number divisible by 100)
except every 400 years (year number divisible by 400)
...

I think there is another exception, but it's on 4000 years or something
and won't occur in my lifetime.

It's interesting to note that the rule of having leap year every four years
except every 128 years would be accurate for over 30,000 years.  The orbital
elements of the earth would probably change noticably before then.

J. Giles