Well thats why we arrange these things waay in advance, so other plans can be adjusted etc. We'll wait to see what the majority of people think for Jul 7th, we can't just change it because one person is busy (not that anything is far from being finalised), as a date will never get sorted that way.
7th should be ok for me too, but either way I'm not going to push for another date just because I'm a 'maybe', as I'd be a 'maybe' for most dates to be honest.