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RE: Internal inconsistency wrt year 0000

From: Ashok Malhotra <ashokma@microsoft.com>
Date: Tue, 23 Apr 2002 06:37:52 -0700
Message-ID: <E5B814702B65CB4DA51644580E4853FB01488782@red-msg-12.redmond.corp.microsoft.com>
To: "James Clark" <jjc@jclark.com>, <www-xml-schema-comments@w3.org>
Hi James, good to hear from you!

Our current thinking is that ISO 8601 is in error and we want to request
a change disallowing the year 0000.

You said: 
> Now the year 1BC in the proleptic Gregorian calendar is a leap year.

Where can I confirm this information?  We've been worrying about a
related change in the comparison of durations that is affected by this
information.

All the best, Ashok 
===========================================================


-----Original Message-----
From: James Clark [mailto:jjc@jclark.com] 
Sent: Tuesday, April 23, 2002 6:30 AM
To: www-xml-schema-comments@w3.org
Subject: Internal inconsistency wrt year 0000

The inconsistency between XML Schema Part 2 and ISO 8601:2000 wrt year
0000 
has already been commented on, but there is also a minor internal 
inconsistency.  XML Schema Part 2 disallows year 0000, which means that 
year -0001 corresponds to 1BC (whereas in ISO 8601:2000, 1BC is year
0000). 
Now the year 1BC in the proleptic Gregorian calendar is a leap year. 
However, appendix E uses the formula

  modulo(Y, 400) = 0 OR (modulo(Y, 100) != 0) AND modulo(Y, 4) = 0

to determine whether Y is a leap year.  But this formula makes year
-0001 
not a leap year.  If year 0000 was allowed (representing 1BC), then the 
formula would be correct.

James
Received on Tuesday, 23 April 2002 09:38:24 GMT

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