John,
It’s the second Saturday in June, has been for several years. Which makes it 9th June 2018.
I believe that there will still be a June show in Burton in 2019, but due to it being the Association’s 40th Anniversary, the AGM itself will take place at SWING to pander to the southern based members. Albeit at a greater hindrance to those in the north.
It does mean that the room usually taken over by the AGM will be available for use by exhibits for an enlarged show to celebrate 40 years of the Association. Hopefully, some O14 layouts will be available to fill this space.
Hope that helps,
Andrew