Mark Walberg Led TRANSFORMERS Sequel To Pick Up Four Years After DARK OF THE MOON Four Years Of Backstory Will Separate Transformers 4 From The Last One | Bleeding Cool Comic Book, Movies and TV News and Rumors "The movie is going to continue 4 years on from the attack on Chicago which was in the last movie. So it’s going still to have the same lineage but going in a full, new, different direction and it actually feels really natural how it is going in that direction." Michael Bay Hmmm, maybe a "Ground Zero" homage celebration, with tensions and all in the background?
This is pretty much the case for most of the films. They all have a couple of years set between them.