“As for September 11, let us not too easily grant the Americans possession of that date on the calendar. Like May 1 or July 14 or December 25, September 11 may seem full of significance to some people, while to other people it is just another day.”

Variant: December is the toughest month of the year. Others are July, January, September, April, November, May, March, June, October, August, and February.
Source: Pudd'nhead Wilson

"The Palace of the End" (2003)
Context: Like all "acts of terrorism" (easily and unsubjectively defined as organised violence against civilians), September 11 was an attack on morality: we felt a general deficit. Who, on September 10, was expecting by Christmastime to be reading unscandalised editorials in the Herald Tribune about the pros and cons of using torture on captured "enemy combatants"? Who expected Britain to renounce the doctrine of nuclear no-first-use? Terrorism undermines morality. Then, too, it undermines reason. … No, you wouldn't expect such a massive world-historical jolt, which will reverberate for centuries, to be effortlessly absorbed. But the suspicion remains that America is not behaving rationally — that America is behaving like someone still in shock.

John Pilger, "Blair has made Britain a target" 21 September 2001 http://www.guardian.co.uk/wtccrash/story/0,1300,555452,00.html

[Twin, Alexandra, http://money.cnn.com/2002/08/26/markets/markets_newyork/index.htm, Stocks stage a turnaround, CNNMoney.com, August 26, 2002, 2007-05-27]

Interview "Colonies in space may be only hope, says Hawking" by Roger Highfield in Daily Telegraph (16 October 2001) http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2001/10/16/nhawk16.xml&sSheet=/news/2001/10/16/ixhome.html

" Galloway and Hitchens get down and very dirty http://www.timesonline.co.uk/article/0,,11069-1781608,00.html", The Times, September 15, 2005
During a debate with Christopher Hitchens, September 14, 2005

2011, Remarks on death of Osama bin Laden (May 2011)
Context: On September 11, 2001, in our time of grief, the American people came together. We offered our neighbors a hand, and we offered the wounded our blood. We reaffirmed our ties to each other, and our love of community and country. On that day, no matter where we came from, what God we prayed to, or what race or ethnicity we were, we were united as one American family.
We were also united in our resolve to protect our nation and to bring those who committed this vicious attack to justice. We quickly learned that the 9/11 attacks were carried out by al Qaeda — an organization headed by Osama bin Laden, which had openly declared war on the United States and was committed to killing innocents in our country and around the globe. And so we went to war against al Qaeda to protect our citizens, our friends, and our allies.

On the National Security Agency's warrantless surveillance under President George W. Bush, in [O'Keefe, Ed, Feingold Calls for Bush's Censure, https://abcnews.go.com/ThisWeek/Politics/story?id=1715495&page=1, 20 August 2018, ABC News, March 12, 2006]
2006

56 min 20 sec
Cosmos: A Personal Voyage (1990 Update), The Shores of the Cosmic Ocean [Episode 1]