The photo itself is undated. The AP story says that the US Military offered that date for the photo after, at first, trying to prevent further publication.
The date of the photo may be exactly as reported. Or not.
What I find interesting is that sometime prior to Sept 13 (when the photo was first published) a drone happened to be flying over a cemetary in Afghanistan. Is this the only large gathering of Taliban spotted by drones? If not, we should have seen more photos over the course of years and this one would not stand out as being unusual in any way.
It is only interesting because it is unique.