The code in USAC, NASCAR, and IndyCar states if fewer than half the laps are completed or if the race is unable to start, the event is resumed on a later date, usually the next day. With the introduction of lights at numerous oval tracks, the time frame for resuming a rain delayed race on the same day has been largely expanded. Some races stopped during the day for rain have seen the track dried, and the race completed later in the evening on the same day. Since the 2017 season, all NASCAR national series utilize a format in which races are divided into three or four stages, with a competition caution after each; a race is considered official following the conclusion of the second stage, which is typically positioned around two quarters of the scheduled distance.