It appears to be from early October 2012, perhaps Oct. 13, since there's an event at the Yards Park that could be Snallygaster, plus the postseason signage is on the Nats diamond, and the trash transfer station's final demolition is just underway.

As I've done with each new image since 2002(!), I've posted it on my Images from Above page, where you can choose to display multiple versions going back to 1949(!!) to compare them.

I also always highlight the changes from the previous image, which in this case means the completion of Capitol Quarter's second phase, the Teague-Yards bridge, the Florida Rock site clearing, the 11th Street Bridges construction, and more.

If you want to zoom into the historic images, Google Earth allows you to view archival versions. (For the record, I love the ghostly images of Nats Park under construction in the 2006 shots.)