I've been looking around for an answer to this question since you wrote it. It's been REALLY frustrating to find, since Congress' papers aren't anywhere readily accessible that I can find. However, I did FINALLY come across this.. The Pennsylvania Evening Post of Philadelphia published an account of the Battle of Bunker Hill in their July 1, 1775 edition. The report was written on June 21st, and would have had to arrive by June 30 to be included in the July 1 paper. So you're looking at a maximum of 9 days, with the very real chance of express riders shaving maybe a day or two off the time.