Dark Fantasy?

could be. maybe that's best left up to the editor. he'll put your story in whatever category he deems best. i've always approached any story from the standpoint of being aware of genre conventions, but don't let those take over the story i want to tell, either.

Hmmm, Dark Fantasy? Occurs at night, right? (wink, wink, nudge, nudge)

Yes, a horror fantasy will often be considered such, but it's best to leave that designation to the editor as preyer suggested.