W3C home > Mailing lists > Public > public-media-annotation@w3.org > April 2011

getting rid of xsd:dateTime ?

From: Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>
Date: Tue, 05 Apr 2011 17:55:16 +0200
Message-ID: <4D9B3B64.50805@liris.cnrs.fr>
To: "public-media-annotation@w3.org" <public-media-annotation@w3.org>
Hi all,

there seem to be a recurring problem with dates and the ma: ontology. I
encountered it, Martin encountered it, I know that Joakim also did...

The fact is that most metadata formats we are dealing with allow dates
to be more or less precise, like

* just a year
* a year and a month
* a year, a month and a day
* ...

while xsd:dateTime imposes to us to commit to a 1sec precision...

I suggest we change the range of date properties to rdfs:Literal, and
specify in the documentation that they should be of the form
YYYY[-MM[-DD[Thh[:mm[:ss[.fff]]]]]], to be interpreted as an incomplete

This hinders interoperability a tiny bit, but not as much as inventing a
day and an hour for media resources for which we only know the year.


To all, some general remarks and conclusions

* as most metadata format are more permissive regarding dates than
xsd:dateTime, I suggest we simply use rdfs:Literal for all our date
properties, and explain that it should be of the form
Received on Tuesday, 5 April 2011 15:55:42 UTC

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