I hope you are asking for an imaginary day because my romantic life is nonexistend
this is a hard one hmmmmp I can’t really say how I would perceive really a “romantic” day, it would be more about if the person I am with, give me the reasons to truely feel an emotional and mental conection of that type with them, so, having a special romantic day with them would actually involve anything really, eating at a fine restaurant at nite or snacks while watching a hardcore horror movie, anything with someone like that would give me a feeling of being into a romantic situation actually I guess