Rod Fergusson has recently tweeted on his twitter (twitter.com/GearsViking)...
the hours that the Gears of War 2 20x XP event will take place:
So 20x XP SDCC Event is going to run exactly SDCC hours - July 22nd, 12:30 PM EDT till July 25th, 8 PM EDT. Get your wings!
So there you go folks! Jump onto GOW2 during those hours to take part in the biggest XP event ever!