Constitution Memorial Day (kenpou kinenbi), on May 3rd is the second of three "Golden Week" holidays. This day remembers the beginning of the enforcement of Japan's Post-War Constitution on May 3, 1947, created during the American occupation of Japan, after World War II.

General Douglas MacArthur held a pivotal role in the establishment of a new government in Japan, but representatives from many nations gave input in designing the new Constitution and the parliamentary form of government which was to follow.