@nynycasino1234 , as noted above, it is certainly possible to tour both UNC and Duke in a day. Is it advisable? No, unless you are really rushed for time, or plan to return for another visit.
We made the mistake of visiting both in one day. First, with the information session, tour, visiting a class, talking to people, you just run out of time and energy. Second, everything about Duke is first rate & professional; the admissions office, guides, everyone–they know what they are doing. Carolina, not so much (highly variable experience depending on the admissions officer and guide). I think you need a separate day to give each school a fair shake.
The upshot of our rushed visit was our daughter loved Duke, and put UNC at the bottom of her list. (But it worked out: she still loves Duke as a student there.)