Double Duty also referred to as the Indy-Charlotte Double or Memorial Day Double, is an auto racing term centered around two events held on Memorial Day weekend in most years. The two events are the annual Indianapolis 500, which is the most important Indycar Series race held at the Indianapolis Motor Speedway in Indiana, and the annual Coca-Cola 600, which is a NASCAR Cup Series race held at the Charlotte Motor Speedway in North Carolina. These two events are regarded as significant events for their respective series, as the Indianapolis 500 is the most prestigious race for Indycar while the Coca-Cola 600 has for years been considered one of NASCAR's most important races, as it is the longest event on the schedule.