 of XML Schema builtin datatype <code>date</code> or <code>g*</code>.</p>
 
 <p>For example, an instance of <code>gYear</code> can be created invoking this factory 
 with <code>month</code> and <code>day</code> parameters set to 
 <A HREF="../../../javax/xml/datatype/DatatypeConstants.html#FIELD_UNDEFINED"><CODE>DatatypeConstants.FIELD_UNDEFINED</CODE></A>.</p>
 
 <p>A <A HREF="../../../javax/xml/datatype/DatatypeConstants.html#FIELD_UNDEFINED"><CODE>DatatypeConstants.FIELD_UNDEFINED</CODE></A> value indica