Yes, it takes place in the future, about twenty years after the Great Hinamizawa Disaster. It's an alternative ending to the Atonement arc as an epilogue, but it's part of the question arcs for the manga, albeit as a side-story. It's an interesting arc that is a bit different from other arcs. Beyond Midnight is more of a ghost story than anything else, but it's beautiful. It was eventually incorporated into the DS port, Higurashi Kizuna, as part of the answer arcs.
You should check it out. It actually has some meaning to the series in a way, even if majority of it is never brought up in mainstream.
I see now. I recall reading something like that on the back. I'd love to have the DS import, but I'd need it translated, and I don't know where I can import things in the first place; Hau-au-au...
BUt what do you mean by, the majority of things aren't brought up? Are you saying something was brought up that I missed?