Thinking way ahead about a party

So I've already determined that I can't manage to fit my 50th birthday party into the calendar in May (much less on my actual b-day) if I don't want all sorts of people to not be able to make it. So I'm currently wavering between pencilling it in on Sunday June 1 and one day or the other of the weekend of June 28-29. Is there anything I'm utterly forgetting that might make one of those days more or less preferable than the others? (The party theme is still nebulous -- defaulting to Food, Friends, and Hanging Out -- although I'm working on coming up with something clever.)