Re: [RSS-DEV] Expressing date range in coverage

["Bill Kearney" <wkearney99@hotmail.com>]

I may have overlooked the use of a Period element.

<dc:coverage>
<Period>start=2002-09-20T20:01:19Z; end=2002-11-01T23:39:19Z;</Period>
</dc:coverage>

This would also allow inserting the spatial element as well.  That could be a
little more problematic in that the assumption is the coverage element here is
about the range of the items.  Putting a spatial element in here might be
construed as an expression of location in relation to the temporal range.
That's a more complex issue.  If spatial data is desired on a per item basis it
should be added inside the items themselves.  Now, which location best expresses
an item's spatial location is a whole other problem.  But the Dublin Core does
allow for location data and a coverage element is the place for it.

This leads to examples like:

<dc:coverage>
<Period>start=2002-09-20T20:01:19Z; end=2002-11-01T23:39:19Z;</Period>
<Point>east=-77.12; north=38.99; projection=WGS84; name=Bethesda, MD
USA;</Point>
</dc:coverage>

Note: DCSV within an element does not wrap the data in quotes.  Moving the data
up into attributes would, of course, require quotes.

Or perhaps

<dc:coverage>
<Period>
    <start>2002-09-20T20:01:19Z</start>
    <end>2002-11-01T23:39:19Z</end>
</Period>
<Point>
    <east>-77.12</east>
    <north>38.99</north>
    <projection>WGS84</projecton>
    <name>Bethesda, MD USA</name>
</Point>
</dc:coverage>

Or to /really/ get funky

<dc:coverage>
<Period>
    <start rdf:value="2002-09-20T20:01:19Z" />
    <end rdf:value="2002-11-01T23:39:19Z" />
</Period>
<Point>
    <east rdf:value="-77.12" />
    <north rdf:value="38.99" />
    <projection rdf:value="WGS84" />
    <name rdf:value="Bethesda, MD USA" />
</Point>
</dc:coverage>

A coverage element with a point could also be used within an item to indicate a
spatial location.  There are any number of different combinations possible.  I'm
using WGS84 (World Geodetic Survey from 1984) for positioning as it's what my
GPS unit spits out and is what is commonly used.  There are other schemes
possible here but much like alternative temporal schemes, within the context of
newsfeed items a subset is probably a very wise choice.

A question that develops is what namespace/prefix should be applied to the
<Period> element?  Or even what letter case?

-Bill Kearney

Further reading:
http://dublincore.org/documents/dcmi-period
http://dublincore.org/documents/dcmi-point/
http://dublincore.org/documents/dcmi-box