Did you ever hear a theory that I found very thought provoking? That 9/11 was scheduled to be a week later on 9/18 but they had to bring it up up due to circumstances.
Why would it be interesting if it occurred on 9/18?
Immediately after the attack, a news story surfaced that Jews had stayed home on the day of the attack- with the implication that they knew ahead of time. The story release in Lebanon came immediately after the attack. Pre-prepared it seems.
Well guess what, if the attack had been on 9/18, many Jews would have stayed away from work and the WTC on that day.
Sept 18, 2001 was the first day of Rosh Hashana.
There would have been absolute proof of Jews staying away (ie knowing in advance) for those not understanding the significance of Rosh Hashana.
That's quite an interesting hypothesis. Next step would then be to think about what could have forced the hijackers to go early.
Could it have to do with the anthrax letters? Accidental contagion?