code: private static Calendar parseExpectedXsdDateTimeValue(final RDFNode node) {
          final Object value = node.asLiteral().getValue();
          if (value instanceof XSDDateTime) {
              return ((XSDDateTime) value).asCalendar();
          } else {
              throw new IllegalArgumentException("Expected an xsd:dateTime!");
          }
      }
docs: Parses an RDFNode that is expected to be a literal of type xsd:dateTime into a Java Calendar
  object.
  @param node a node representing an xsd:dateTime literal
  @return a Calendar representation of the expressed dateTime