Half-staff question 9/6?

[client32]

I think it was Wednesday, but could have been Tuesday, was there a reason for the flags to be at half-staff?

Two of the houses that I drive by to and from work fly flags.  They were at half-staff on that day.  I didn't look real hard, but I couldn't find a reason.

[TarpleyG]

I suspect that a lot of people are doing that out of respect for 9/11.  I, however, will be flying my flag high and proud on 9/11.  I think there is something in flag etiquette that dictates that one can fly a flag half-mast for a certain period but not after.  Do you fly your flag half-mast on Memorial Day?  I don't.  I might be wrong and YMMV but that's my take...the mourning period is over and now it's time to get down to business.

Greg