Sunday would be fine for us. I don't want a reputation for being bossy (no comments please) but we'll co-ordinate catering if that's an invitation. However, we're not precious about it and happy to fall into line if someone else wants to take it on.
As Jenny and Chantal have already said - let's try to get as many as possible there, at least for lunch. We don't have to do the whole crocodile/school visit in line stuff, but a get together feast is a good opportunity for all of us.
It's the weekend before my 50th, so I'll be enjoying the final days of middle age.
I never was that good at maths......