I found out about this recently, and I’m not sure if this is old news, but Halo 4 is sort of real time. What I’m saying is that Halo 4 takes place in 2557, which is 5 years after Halo 3, which takes place in 2552. The cool thing about this is that Halo 3 came out in 2007 and Halo 4 comes out in 2012, which is also 5 years.
Not exactly a feature, I would personally call it more of a coincidence.