In the USA, depending on where you are located, there could be a whole lot of noise pollution on that day, with kids lighting fire-crackers etc, during the day & larger, fireworks display type explosions soon after dark.
Depending on what entheogen you are taking & what your preferred set & setting is, this might provide cool OEV, but most people trying to "make contact" while in DMT hyperspace, probably won't want to be disturbed by explosions going on outside.
So timing lift off to be late, like 11:00pm-3:00am in the USA, would be great!!
I don't know how much of this goes on in other parts of the globe, I'm assuming the 4th of July is more of an American holiday...
I agree with doing these on Saturdays, so the most people can participate though!!
I don't think Tuesday would work out very well for most people.
WS