The precise count of hours Sumatran rhinoceroses rest in a day is not accessible in the information I was educated on. However, similar to the majority of mammals, they necessitate rest for their overall health. Rhinoceroses, including the Sumatran rhinoceros, are lively during daylight hours and participate in actions such as eating, relaxing, and slumbering. They probably rest for several hours, but the rest may be divided into shorter intervals. To present an accurate number, additional investigation and scientific studies on the sleep patterns of Sumatran rhinoceroses would be necessary.