I worked at the NSA as an Arabic Linguist for four years after 9/11. While I was there, two major al-Qaeda attacks targeted European capitals. I suggested to my colleagues at times that attention should focus on the numerical dates AQ seems to favor. If AQ does favor certain dates or days of the week, here is my best guess for why Thursday 8/8 is the date to expect (and hopefully foil) an attack.
We're currently under what probably would have been Code Red Severe were we still using that Color Coded Warning System developed after 9/11.
Current reporting suggested that yesterday, Sunday 8/4/2013,
was a day of particular concern. Since the day has now come and gone
without an attack, one of several things has happened:
1) There never was an attack, the Intel was misunderstood
2) The attack was scheduled for yesterday but either thwarted or delayed
3) The attack is actually scheduled for a different date
But I don't think Sunday 8/4 was ever a good guess for an AQ attack date. They have shown a history of favoring numerically "interesting" numbers.
911 days after 9/11/2001, al-Qaeda (or AQ inspired) staged a major attack against trains in Madrid, Spain, Thursday 3/11/2004.
Their choice of 3/11 was certainly not a coincidence. And psychologically, the attack has the effect of making people wonder every time an 11th rolls around on the calendar whether an attack might be planned.
Now, I have experienced first hand how people can go a little crazy or superstitious about numbers when under duress. When I was in Iraq in 2004, our base was the target of a mortar attack. Freaked us out, obviously, had us all running for our lives to cover. I will admit that all of us had gotten lazy about wearing our body armor and/or helmets. And it wasn't surprising that people started wearing it again regularly. Until a few days later when we all got lazy again. (The stuff weighs 40 pounds and since we were already behind twenty foot tall concrete walls, it just didn't seem necessary.)
Eleven days later, our base was again the target of a mortar attack. Immediately thereafter I noticed people starting to say that we now know the terrorists' Modus Operandi! They attack us every eleven days! (And wasn't 9/11 an 11?) And people actually counted it forward to determine the day of the next attack. And the base was abuzz with talk when that day rolled around. People were once again wearing their armor, ready for the mortars to fall down any second.
The day came and went without incident. And the base wasn't targeted again while I was there. (It was hit badly two weeks after I left and they eventually moved those operations to a safer spot.)
Then came the London Bombings. Thursday morning, 7/7/2005. I will never forget it. I had just arrived early morning to my work station in the Counter Terrorism Office at the NSA. I opened my email and saw the reports. As you can imagine, I was emotionally shook, wondering if there was something we had somehow missed that could have prevented it. (There wasn't.)
Now, we would later learn that al-Qaeda had planned a two stage attack in London. On Thursday 7/21/2005, two weeks after 7/7, there were four attempted bombings, from the same bomb making materials as the earlier event. But the chemicals had degraded enough in those two weeks that the bombs fizzled, thank God.
But again, I don't think selecting exactly two weeks later as the follow-on attack was a coincidence. All of this displays a tendency to plan based on favored days.
9/11/2001 was a Tuesday. 3/11/2004 was a
Thursday. 7/7/2005 was a Thursday. 7/21, though not numerically interesting, was a Thursday.
So, for what it's worth, the wild speculation of this former NSA Agent is that Thursday 8/8 is the most likely date. We have the confluence of a Thursday and a repeated digit just like 7/7. It's also Eid al-Fitr, the end of Ramadan. Sunday 8/11 would be my next guess. And I hope I'm wrong because my former colleagues and other intelligence and law enforcement thwart it all, if there was anything to thwart to begin with.