1 JULY 2013
If you feel anxious about them selling out, that is. This applies only to official Comic-Con t-shirts, which come in four flavors this year, and the pre-sale ends on 11 July at 5:00 pm PST.
To be clear, your shirts won't be shipped to you. You have to pick them up yourself at the Marriott Marquis in the Santa Rosa Room.
See here for prices, sizing and the magical order button.