The SDO specification does not provide workable support for durations at present. This is documented in the following JIRAs opened against the specification:
http://www.xcalia.com/support/browse/SDO-95 (Fixed in SDO 2.1)
http://www.xcalia.com/support/browse/SDO-189 (Future SDO 3.0)
The current SDO CTS duration tests (i.e. date formats starting with 'P') are passing against tuscany because the test (DateConversionTest.testToDateFormats) is only testing that the returned date is not null. The tuscany implementation of duration appears to be broken so it is misleading that the tests are passing.
I propose that we move the duration tests to the UnderReview test suite for now.