Richard Reid attempted to bring down AA Flight 61 on 12/22/01 (which coincided with the end of Operation Desert Fox)... then there was the thwarted Millenium attack of L.A.X on 1/1/2000 (not sure of the significance of that date, aside from the obvious)...
The latest round with Iraq surely has provided the Islamists with a whole new series of dates to be commemorated with bombs and carnage... unfortunately, we won't know what those dates represent until after that fact.