> does this mean they are creating pockets of "different" time?

No. The rate at which time passes - if you compare different places - depends on the location. As an analogy, if someone in city A earns more money than someone in city B doing the same job then you can see how their accumulated money will differ more and more over time, but nothing dramatic happens if someone moves from city A to B or vice versa.

This is not unique to a black hole, on a smaller scale you have that every time gravity is involved. Even on Earth - GPS satellites take that into account.