custom format in JSON for DateTimeField with mongorecord
===

im using lift-mongodb-record 2.4.
All of my MongoRecord models include the following [DateTimeField][1] field, eg:

    object created_at extends DateTimeField(this)

when i call asJSON on this model, it'll parse the date into a string e.g.

    Mon, 16 Jul 2012 21:26:58 GMT

I would prefer other formats (eg. ISO 8601, depends on the acutal use-case) 

*how and where would I set up a custom format?*

thanks

  [1]: http://scala-tools.org/mvnsites/liftweb-2.3/net/liftweb/record/field/DateTimeField.html