I think only one day is appropriate, although anyone is welcome to fly a flag on their own on any summit at any time of any day. My preference is 9/11 for 2005. The question for the future is: how much do we allow the availability of hikers to affect the memorial? It’s a “9/11 Memorial Hike” … without hikers, it’s not much of a hike. Too far from 9/11, and its meaning is diminished.
Personally, I like the weekend because I come up the night before and stay the night after. I may even backpack again for the day before. But even if it were only a day trip, many people just don’t have that kind of vacation time available to them to take the day off. This is important not only for the participants carrying the flags up, but for those other hikers going up to witness the flags, who want to see the memorial.
And … school will have just started. A weekday will rule out attendance by anyone of school age.
With respect to my comment about keeping it nonconflicting with the VFTT Gathering, obviously the 11th is the 11th. It’s just that if we were choosing between the weekend before and the weekend after, a 50:50 decision, then keep VFTT’s weekend in mind.