Today is the official memorial day for China's victory in the War of Resistance against Japanese Aggression. Now, let's take a look at why September 3rd was chosen and made a national holiday.
今天（9月3日）是中國人民抗日戰爭勝利的官方紀念日。現在我們一起來看看為何將9月3日定為全國性的紀念日。

Japan's announcement of surrender actually happened on August 15th, 1945. A little after noon, Japanese emperor Hirohito announced his country's acceptance of the terms of the Potsdam Declaration, and its unconditional surrender. The message was broadcast across the nation over radio.
1945年8月15日，日本宣布投降。當天中午時分，日本裕仁天皇宣布日本接受《波茨坦公告》，無條件投降。這一消息通過電臺廣播傳遍全國。

However, without the formal signing over the terms of the surrender, it didn't have any legal standing. So, on September 2nd, representatives from Japan, China and eight other Allied powers gathered on the deck of the USS "Missouri" in Tokyo Bay. They signed on the Japanese instrument of surrender. The ceremony over 20 minutes, and it was broadcast throughout the world.
不過，投降協議尚未正式簽署，日本的投降尚不具備法律效力。因此，9月2日，在停泊于東京灣的美國“密蘇里號”戰列艦上，日本代表同中國及其他八個同盟國的代表簽署了日本降伏文書。受降儀式時長20多分鐘，并以廣播形式昭告世界。

The next day, September 3rd, the Japanese army in China formally surrendered to the Chinese government. The whole of China was in jubilation. Celebrations were held across the country. It marked the first outright victory over a foreign invasion in Chinese modern history. Therefore, September 3rd was chosen, at the time, as the official victory day.
次日，也就是9月3日，中國境內的日本軍隊正式向中國政府投降。全國人民都沉浸在喜悅之中，舉國歡慶。這是近代以來中華民族反抗外敵入侵第一次取得的完全勝利。因此，當時，9月3日就被定為抗戰勝利紀念日。

However, after the founding of New China in 1949, the victory day was reset to August 15th, the date Japan announced unconditional surrender. But two years later, the then-Government Administrative Council switched it back to September 3rd.
然而，1949年新中國成立后，勝利日一度被改為8月15日，即日本宣布無條件投降的日期。兩年后（1951年），當時的中央人民政府政務院重新將9月3日確定為抗戰勝利紀念日。

In 2014, China's top legislative body ratified September 3rd as the "Victory Day of Chinese People's War of Resistance Against Japanese Aggression". It then officially became a national holiday when it was announced that memorial activities would be held every year going forward. It's hoped the ratification will help people reflect on the war; commemorate the heroic sacrifices; and express China's firm stance of safeguarding national sovereignty, territorial solidarity and world peace.
2014年，全國人大通過決議，將9月3日確定為“中國人民抗日戰爭勝利紀念日”。有關部門宣布，今后每年9月3日都將舉行紀念活動，9月3日也正式成為全國性的紀念日。批準設立抗戰勝利紀念日有望幫助人們反思戰爭，緬懷先烈的犧牲，表達中國堅決維護國家主權、國土完整和世界和平的決心。

Vocabulary
USS: 是United States Steamship的縮寫，指美國船舶。

英文來源：央視網
譯者&編輯：許晶晶