Nintendo has a holiday on the 10th of March each year and is known as the MAR10 Day, and is a day aimed at its most popular character, Mario. The date is a visual pun, the number MAR10 approximates the name of a character, Mario, and the date was already being adopted as an unofficial celebration by fans well before it was officially adopted by Nintendo. With time, the company has made the day a reoccurring international event where the company makes game promotions, tournaments, announcements, and fan activities.
The 2026 version has additional symbolic significance as it is the 40th anniversary of the influential 1985 Nintendo Entertainment System game Super Mario Bros., which is said to have established the modern platforming game. In order to celebrate that milestone, Nintendo expanded the Mario Day to a multi-layered celebration that encompassed digital services, retail offers, community events, and cross-media promotion, based on the larger Mario franchise.
Nintendo organized multiple March activities that extended beyond the March 10 date to create a seasonal celebration for their Mario Day festivities.