Chinese lawmakers have approved national remembrance days to commemorate the Nanjing Massacre and Japan's defeat in World War II, state media said on Thursday, amid bitter disputes over territory and history.
"September 3 was ratified as the victory day and December 13 the national memorial day for massacre victims", the official Xinhua news agency said, reporting decisions by members of the National People's Congress, China's rubberstamp parliament.
Japan invaded China in the 1930s and the two countries fought a full-scale war from 1937 to 1945.
China says more than 300,000 people were slaughtered by Japanese troops in a six-week killing spree in the then capital Nanjing, which began on December 13 1937. Some foreign academics put the figure lower.
It was unclear what significance the formal "national days" will have, although they are not expected to be public holidays.
The Chinese government previously designated as victory day September 3, the day after Japan formally surrendered to the Allies on board the USS Missouri in Tokyo Bay in 1945.
"The approval of the national days has great historical significance and is a necessity in current circumstances," foreign ministry spokeswoman Hua Chunying said following the decision.
Tokyo and Beijing are embroiled in a series of rows, including a long-running diplomatic spat over disputed islands in the East China Sea. Tensions rose further last month when Japanese Prime Minister Shinzo Abe visited the Yasukuni shrine, which honours Japan's war dead, including convicted war criminals.
Chinese officials often call on Japan to "reflect" on its past, while Tokyo says its neighbours use history as a diplomatic stick to beat it with.