Arbor Day is observed in China and Taiwan every March 12. In China, this national holiday was established in 1979 to improve the ecological situation and is also known as National Tree Day. The origins of Arbor Day in China can be traced back to Dr. Sun Yat-sen, who advocated for tree planting and reforestation efforts. Although his initial proposal in 1914 was not taken seriously, his contributions were recognized posthumously after his death on March 12, 1925, leading to the establishment of Arbor Day to honor him. On this day, citizens in mainland China are required to plant 2-3 trees, while in Taiwan, Arbor Day is celebrated as an unofficial holiday.