Occupation stamps (Hong Kong) Issued 1942 - 1944 Japan occupied Hong Kong for three years and eight months from December 25, 1941 to August 1945, immediately after the start of the Pacific War. The Hong Kong overprint stamp was issued on January 22, 1942. In April 1945, the postage was raised due to rapid inflation during the war, and three new stamps were issued. After that, it lost its effect due to the defeat of Japan in August 1945 (Showa 20).