We are trying to talk to a (possible)Java WebService from .NET 3.5 using WCF. The WebService defines a Timestamp object which seems to be a datetime without the decimal milliseconds.

WCF decided .NET would use a datatime as the object backing in the proxy class. When sending objects with the timestamp to the Java WebServer the datetime is serialized and includes the miliseconds. This results in a Fault.

How do we a) Cause .NET to select a custom class we implement (So we can format the message) or b) Cause WCF to generate the datetime based on the XSD files included with the WSDL?

Issue Definition: Timestamp needs to look like: 
2010-01-01T01:01:01-07:00

Yet .NET generates a timestamp with decimal seconds like:
2010-01-01T01:01:01.1234-07:00