I am trying to search for threads started on a particular date, which I apparently cannot do (9-11-2001, for anyone interested…). So, I decided to search for “World Trade Center” instead (Keywords: World Trade Center, Find Posts From: A Year Ago and Older, Sort Results by: Thread Start Date Ascending.
It finds 5 threads started in 2000, but then it skips to a thread started on 08-27-2001 and from there to 04-12-2002. I know there are posts from 9/11 containing the words World Trade and Center. For example this one (which is what got me started in the first place): World Trade Center Plane Crash