McDonald's Day is observed on April 15, celebrating the anniversary of the first McDonald's restaurant opened by Ray Kroc in Des Plaines, Illinois. While Kroc is credited with the establishment of the franchise, the original founders were the McDonald brothers, Richard and Maurice, who opened their first restaurant in San Bernardino, California. The day honors both Kroc and the McDonald brothers, recognizing their contributions to the fast-food industry. Typical customs for McDonald's Day include celebrating the brand's global impact, with many people around the world acknowledging its significance. The event serves as a reminder of the evolution of the fast-food concept, which began with a focus on hamburgers and a simplified menu.