Ahem ... well, found this on
For example the time for transition training from the A330/A340 Family is expected to be six to 10 days, considerably less than the 25 days needed for transition training without commonality.
And this is taken from
The usual time for transfer training from the A330 or A340 is eight to 12 days; considerably less than the 25 needed for transfer from aircraft without this commonality.
Le Beaujolais Nouveau c'est arrivé, Airbus?