OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

Re: [xml-dev] limits of the generic

[ Lists Home | Date Index | Thread Index ]

```Hi Jeni,

Yes, the comparison of these durations is determinate.  However, it is
inconsistent with

2004-02-29 + P1Y1D > 2004-02-29 + P365D

which is false according to the algorithm you described, (but would be true
for any starting date which is not 02-29  in a leap year).  In other words,
I cannot deduce from x > y (P1Y1D > P365D) that a + x > a + y.  I realize
its a different > operator (for durations vs. dates), but if they are not
defined consistently there is a problem.

Jeff
----- Original Message -----
From: "Jeni Tennison" <jeni@jenitennison.com>
To: "Jeff Greif" <jgreif@alumni.princeton.edu>
Cc: "John Cowan" <jcowan@reutershealth.com>; <xml-dev@lists.xml.org>
Sent: Sunday, September 29, 2002 11:55 AM
Subject: Re: [xml-dev] limits of the generic

> Hi Jeff,
>
> > Another astonishment is that the algorithm described makes P1Y1D >
> > P365D indeterminate, even though in our naive understanding, even
> > including the idea of leap year, a year and a day is always at least
> > 366 days.
>
> was only suggesting comparing durations by adding them both to a
> particular date and comparing the results when the result of comparing
> the durations directly is undefined.
>
> Your example of P1Y1D > P365D isn't undefined, however, as I
> understand it. P1Y is between 365 and 366 days. P1Y1D is therefore
> between 366 and 367 days. P1Y1D therefore *must* be more than P365D.
>
> On the other hand, P1Y1D > P366D, for example, is undefined if you
> just compare the durations, because P1Y1D *could* be more than P366D.
> At that point, *one way* of resolving it would be to add them both to
> today's date (or another date of your choosing) and comparing the
> resulting dates.

```

 News | XML in Industry | Calendar | XML Registry Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement Copyright 2001 XML.org. This site is hosted by OASIS