Keygrip
To answer the second part of your question first - no it does not count if you do not do it all on one day (unless there is a valid reason why you did not do so, e.g. weather, tech problems).
I checked this with the CAA last year and I was told that the one day rule had been implemented early last year although the change has not been included in (e.g.) LASORS.
The first part of your question is not so clearcut. The rule does say "a cross country flight in the course of which full stop landings at two airfields other than the airfield of departure shall be made". In theory, your example would therefore be valid, but I do not think I would take that risk!
Linda