I believe I am missing something obvious here. When I request a JSON response from an OData service I get a different result for the DateTime properties than I do when I req
This reply might get voted down (!!) but an alternative solution is to just change your WCF Service to return the dates in a more friendly way.
Here's some sample JSON from my WCF service, showing a UpdateDateOriginal value (using the annoying default formatting that WCF has used for my DateTime value), and a friendlier UpdateDate version of the same DateTime value.

I've posted the code to do this in the following article:
Change default date serialization in WCF