Just check all the dates when you're in Edinburgh, and good days for a meeting should be obvious after we've all selected dates.
My plans have suddenly had to change and are still uncertain. I will be there, but I currently don't know dates, so I'll have to give them next week.
The Edinburgh Festival is 14th August - 6th September
The Edinburgh Festival Fringe is 7th August - 31st August
The Edinburgh Book Festival is 15th - 31st August
So the poll runs from 7th August for 29 days, with one "I'm not in Edinburgh then" for completeness.