Invention Day is observed in Japan every April 18, commemorating the anniversary of the Patent Monopoly Act, which established the first substantial patent law in the country in 1885. This day celebrates the significant role that patent law has played in Japan's industrial modernization, marking the beginning of the industrial revolution shortly after the act's promulgation. The first Japanese patent was granted to Hotta Zuisho for an anticorrosive paint, highlighting the importance of innovation in the nation's development. Established by the Ministry of International Trade and Industry in 1954, Invention Day has been celebrated annually, reflecting the government's commitment to encouraging new industries and fostering economic growth through inventions. Over the years, Japan's patent law has undergone numerous amendments and revisions, but the celebration of Invention Day remains a tribute to the nation's inventive spirit and its impact on the economy.