Date offset issue

[giacomociti]

The following test:

• core/node/minInclusive-003.ttl

fails due to a strange date offset issue (to be further investigated).

[giacomociti]

the problem is due to pred:dateTime-less-than-or-equal when comparing a date with an offset and another without.

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
@prefix pred: <http://www.w3.org/2007/rif-builtin-predicate#>.

{
    ?t list:in ( 
        "2002-10-10T12:00:00-05:00"^^xsd:dateTime
        "2002-10-10T12:00:01-05:00"^^xsd:dateTime
        "2002-10-09T12:00:00-05:00"^^xsd:dateTime
    ) .
    ("2002-10-10T12:00:00"^^xsd:dateTime ?t) pred:dateTime-less-than-or-equal ?lte
}
=>
{
    ?t rdf:value ?lte .
} .

produces

"2002-10-10T12:00:00-05:00"^^xsd:dateTime rdf:value true.
"2002-10-10T12:00:01-05:00"^^xsd:dateTime rdf:value true.
"2002-10-09T12:00:00-05:00"^^xsd:dateTime rdf:value false.

The correct result should be false in all cases, according to the XSD spec:

Note: Since the order of a dateTime value having a ·timezoneOffset· relative to another value whose ·timezoneOffset· is absent is determined by imputing time zone offsets of both +14:00 and −14:00 to the value with no time zone offset, many such combinations will be ·incomparable· because the two imputed time zone offsets yield different orders.