This is what I have...
25/26 March Cadwell Park – TBC
23 April Brands Hatch – Indy
6/7 May Assen
11 June Castle Coombe
8 July Oulton Park
13 August Donington Park
2/3 September Snetterton (long race Saturday, two short races Sunday)
8 October Cadwell Park
...is that the latest? Not that it matters yet.