Only Chrome natively parses ISO8601 into js Date objects. Duck punch an ISO8601 string with this utility js function, or Rails solution.

json_dates.rb

# If you're building the JSON provider with Rails,
# add to the as_json method of TimeWtihZone by adding
# this file to your config/initializers/

class ActiveSupport::TimeWithZone
    def as_json(options = {})
        strftime('%Y/%m/%d %H:%M:%S %z')
    end
end

parseISO8601.js

// Forced to parse it with js?

function ISO8601(date){ 
  var a = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/.exec(date);
  if (a) {
    return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], +a[5], +a[6]));
  }
}
// pattern via http://stackoverflow.com/questions/2526121/how-to-format-json-date-in-javascript