What BG "weekend"

Hi All. The system confuses me here a bit and wanted to see if anyone know the exact facts.

So we all know that retails usually have BG Weekends which starts on thursday and ends on monday or tuesday or something.

Here i noticed they have new NPCS for it everyday (you can always tell becasue the NPCS is spread out in the major cities)
However today i noticed that Shattrath had WSG NPCS and Stormwind had AB npcs which got me confused.

1, was i wrong, is it not a "daily BG weekend" that gives increased honor?
2, is it 2 different on weekends and thats why the cities have different?
3, was 9/11 an inside job?

Cheers