McDonald's Day is celebrated annually on April 15 by fans of the fast-food chain, marking the anniversary of Ray Kroc's first franchised McDonald's restaurant in Des Plaines, Illinois. This day serves as a nostalgic tribute to McDonald's, which has grown to operate over 36,000 locations globally, showcasing its significant influence on the food industry. Celebrations may include starting the day with a breakfast at McDonald's, hosting themed parties featuring menu favorites like Big Macs and McNuggets, and engaging in culinary challenges such as recreating the Big Mac at home. Additionally, fans might enjoy a movie marathon featuring films like "The Founder" and "Super Size Me" to reflect on the brand's history and impact. Overall, McDonald's Day is a time for appreciation and reflection on the brand's role in shaping food convenience and culture worldwide.