The 24 Hours of Daytona, currently known as the Rolex 24 At Daytona for sponsorship reasons, is a 24-hour sports car endurance raceports  held annually at Daytona International Speedway  in Dayotona Beach, Florida. It is run on a 3.56-mile (5.73 km) combined  course , utilizing portions of the NASCAR tri-oval and an infield road course. Since its inception, it has been held the last weekend of January or first weekend of February, part of Speedweeks, and it is the first major automobile race of the year in the United States. It is also the first race of the season for the TUDOR United SportsCar Championship.