Improper import of xmlschema:gYear property

[frodeseverin]

I am on OntoWiki with Virtuoso backend (virtuoso 6.1).

I use xmlshema:date and xmlschema:gYear to represent birth dates and death dates. gYear is used in cases where only the gregorian year is known. However gYear seems to be improperly imported into the database when I use 'Add data to knowledgebase'.

Upon import OntoWiki adds '-01-01T00:00:00+02:00' to the gregorian year, althoug this is not mentioned in the Turtle data source.

In my .ttl files the property is coded such:

<http://data.bbib.no/BFO/sofie_bull_oevrevik> a schema:Person ;
    schema:birthDate "1902"^^<http://www.w3.org/2001/XMLSchema#gYear> ;
    schema:deathDate "2001"^^<http://www.w3.org/2001/XMLSchema#gYear> ;

The information is stored such after import:

ns2:sofie_bull_oevrevik ns1:altName "Øvrevik, Sofie Bull Grieg" ;
                        schema:birthDate "1902-01-01T00:00:00+02:00"^^xsd:gYear ;
                        schema:deathDate "2001-01-01T00:00:00+02:00"^^xsd:gYear ;

Contrast this with the information for H.C. Andersen:

Source

<http://data.bbib.no/BFO/h_c_andersen> a schema:Person ;
    schema:birthDate "1805-04-02"^^<http://www.w3.org/2001/XMLSchema#date> ;
    schema:deathDate "1875-08-04"^^<http://www.w3.org/2001/XMLSchema#date> ;

Imported

ns2:h_c_andersen ns1:altName "Andersen, Hans Christian" ;
                 schema:birthDate "1805-04-02"^^xsd:date ;
                 schema:deathDate "1875-08-04"^^xsd:date ;

[white-gecko]

I can also reproduce this problem

[white-gecko]

According to http://www.w3.org/TR/xmlschema-2/#gYear “gYear represents a gregorian calendar year. … e.g. lexical 1999 to represent the whole year 1999 …” so it shouldn't be replaced by just one day of the year

[frodeseverin]

Thanks for clarifying. This is exactly what I ment to say.

My post was a little dull on that point, and also a little bloated with details.

[white-gecko]

maybe someone can find out if this is a virtuoso issue or an ontowiki issue. Either by testing it with MySQL back-end or by loading such data directly to virtuoso.

[knudmoeller]

Just stumbled over this thread (while looking for the cause of a similar problem querying DBpedia): the problem seems to be directly Virtuoso-related. See this mail: https://www.mail-archive.com/virtuoso-users@lists.sourceforge.net/msg04612.html

[white-gecko]

This is a virtuoso issue (so I will close it here). I've checked this by directly importing gYear data into virtuoso and exporting it afterwards. I could see the same behavior as described by @frodeseverin .

As a workaround I'm also reading the datatype to implement an exception in the site-extensions date helper: https://github.com/AKSW/site.ontowiki/blob/develop/helpers/Date.php