Maybe Roland's time is in the year 3000 like previously stated. Maybe there was some kind of nuclear war. But I think that his world is connected to the Stand. Roland's world could be a world that evolved from the remnants of Boulder free zone. One of the founders of the free zone commitee (Glenn Bateman) talks about people reverting to magic and worshiping things like the sun and whatnot when an enlightened civilization dissapears. Roland's society and world seem like a world regressed with remnants of technology surrounding it. The wastelands could be leftovers from the nuclear explosion caused by God to destroy Flagg's society. The places and people could have been different but it could be a different version of that sequence of events. I see many connections between the Stand being the beginning of Roland's world. I am sure of one thing though, throughout the sets of the multiverse, every outcome and every connection are invariably achieved and being played out. King's writings are just the ones he tells about. So if you have a problem with the way he brought some things about, know that in a world other than these, there is a completely different set of circumstances playing out.