Hi, I'm using Jersey (jax-rs), to build a REST rich application. Everything is great, but I really don't understand how to set in JSON Marshalling and Unmarshalling converting option for dates and numbers. I have a User class: @XmlRootElement public class User { private String username; private String password; private java.util.Date createdOn; // ... getters and setters } When createdOn property is serialized, a string like this: '2010-05-12T00:00:00+02:00', but I need to choose date Pattern both, to marshall and unmarshall. Someone knows hot to do that? Thank's a lot, Davide.