Taiwan Retrocession Day

Taiwan Retrocession Day 臺灣光復節
Observed by	Taiwan
Type	Historical, cultural, nationalist
Date	25 October 1945
Frequency	annual

Taiwan Retrocession Day (Chinese: 臺灣光復節; pinyin: Táiwān guāngfùjié) is an annual observance and unofficial holiday in Taiwan to commemorate the end of 50 years of Japanese rule of the island and its handover ("retrocession"; see Controversy section below) to the Republic of China on October 25, 1945.

Taiwan, then more commonly known to the Western world as "Formosa", became a colony of the Empire of Japan when the Qing Empire lost the First Sino-Japanese War in 1894 and ceded the island with the signing of the 1895 Treaty of Shimonoseki. Japanese rule in Taiwan lasted until the end of World War II.

In November 1943, Chiang Kai-shek took part in the Cairo Conference with Franklin D. Roosevelt and Winston Churchill, who firmly advocated that Japan be required to return all of the territory it had annexed into its empire, including Taiwan and the Penghu Islands. Article 8 of the Potsdam Proclamation, drafted by the United States, United Kingdom, Soviet Union and China in July 1945, reiterated that the provisions of the Cairo Declaration be thoroughly carried out, and the Japanese Instrument of Surrender stated Japan's agreement to the terms of the Potsdam Proclamation.

...
Wikipedia