The "Y2K問題" (Y2K Problem) refers to a potential computer bug that arose as the year 2000 approached. Many computer systems represented years using only the last two digits, meaning that the year 2000 would be read as 00. This could lead to errors in date calculations, potentially causing systems to malfunction or crash. To address these concerns, businesses and governments worldwide invested significant resources in updating software and hardware. As a result, when the new millennium arrived, most systems functioned correctly, and major disruptions were largely avoided, demonstrating the effectiveness of the preparations made for the Y2K問題.