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Re: Minimal conformance levels for dateTimes

From: Jim Melton <jim.melton@acm.org>
Date: Mon, 10 Dec 2001 12:38:26 -0700
Message-Id: <>
To: "Ashok Malhotra" <ashokma@microsoft.com>
Cc: <w3c-xml-schema-ig@w3.org>, <w3c-query-operators@w3.org>, <xmlschema-dev@w3.org>
Ashok, et al,

I have no objection to the proposal to require a minimum of 8 fractional 
digits in a conforming processor, but I would like to observe that not all 
platforms (hardware and operating system combined) will be able to provide 
*meaningful* values for the farther right of those digits.  (In other 
words, not all clocks tick at intervals of 100 nanoseconds or less; some 
clocks tick at the microsecond, or even millisecond, level.)  Therefore, we 
must make it clear that a conforming processor must be tolerant of values 
specified to 8 fractional digits of precision, but that they are not 
required to *generate* such values with digits other than zeros on the 
trailing end.  That means that a processor that generated a dateTime value 
of 2002-01-01T12:15:22.12300000 every time it's invoked during the 
millisecond in question would be conforming.


At 03:25 PM 2001-12-09 -0800 Sunday, Ashok Malhotra wrote:
>For this specification, all minimally conforming processors must support 
>year values with a minimum of 4 digits (i.e., YYYY) and a minimum 
>fractional second precision of 100 nanoseconds or eight digits (i.e. 
>s.ssssssss). However, conforming processors may set larger 
>application-defined limits on the maximum number of digits they support in 
>these two situations, in which case those application-defined maximum 
>numbers must be clearly documented.

Jim Melton --- Editor of ISO/IEC 9075-* (SQL)     Phone: +1.801.942.0144
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=  Facts are facts.  However, any opinions expressed are the opinions  =
=  only of myself and may or may not reflect the opinions of anybody   =
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Received on Monday, 10 December 2001 14:41:27 UTC

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