1. No. not that I know of for date datatype field.
2. I usually have another field (or use the same field) of date converted to integer i.e.: int_date_field = Time.now.to_i
So, in my model's rb file, I would add:
property :int_date_field, :integer
This way the recent the date, the higher its integer value (time included). So, descending order will give me most recent first, while ascending order will be oldest first. And my query would look like this:
@results = Model.find(:all, :orderby => :int_date_field, :orderdir => 'desc') # set 'asc' for ascending order
Hope that helps.