FULL PRODUCT VERSION :
java version "1.6.0_05"
Java(TM) SE Runtime Environment (build 1.6.0_05-b13)
Java HotSpot(TM) Client VM (build 10.0-b19, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Windows Vista SP1

A DESCRIPTION OF THE PROBLEM :
DatatypeFactory.newXMLGregorianCalendar mishandles T24:00:00

The javadoc for XMLGregorianCalendar is right - this is legal (the result is a time point of 00:00:00 the next day).

----
hour getHour() 0 to 24 or DatatypeConstants.FIELD_UNDEFINED. For a value of 24, the minute and second field must be zero per XML Schema Errata.
----

The implementation rejects it with an exception calling setHour.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
DatatypeFactory.newInstance().newXMLGregorianCalendar("2008-04-28T24:00:00") ;

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
An XMLGregorian Calendar for 2008-04-29T00:00:00

This is noted in the javadoc and agrees with the XML Schema datatypes spec and errata. The implementation does not meet the spec.
ACTUAL -
java.lang.IllegalArgumentException: Invalid value 24 for Hour field.


ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.IllegalArgumentException: Invalid value 24 for Hour field.
at org.apache.xerces.jaxp.datatype.XMLGregorianCalendarImpl.checkFieldValueConstraint(Unknown Source)
at org.apache.xerces.jaxp.datatype.XMLGregorianCalendarImpl.setHour(Unknown Source)
at org.apache.xerces.jaxp.datatype.XMLGregorianCalendarImpl$Parser.parse(Unknown Source)
at org.apache.xerces.jaxp.datatype.XMLGregorianCalendarImpl.<init>(Unknown Source)
at org.apache.xerces.jaxp.datatype.DatatypeFactoryImpl.newXMLGregorianCalendar(Unknown Source)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
DatatypeFactory.newInstance().newXMLGregorianCalendar("2008-04-28T24:00:00") ;
---------- END SOURCE ----------