I have a problem.
My UI allows people to enter dates in the "dd/mm/yyyy" format, and has a range validator for this.
However, xVal used Date.parse, which in the version of Firefox that I'm using, expects dates in the "mm/dd/yyyy" format.
This means, for example, that someone enters 09th October 2009 (iso:2009-10-09, eu:09/10/2009, us:10/09/2009) and gets a message stating that the date must be after 01/10/2009, as Date.parse parses the date as 10th September, and not 09th October.
I've got jQueryUI installed, so I'm going to look at hooking up Date.parse to use the datePicker's parsing functionality, but this should probably be addresses in the core xVal stuff.