When did China's effective jurisdiction over Diaoyu Island begin?

What is your definition of "effective jurisdiction"?

Diaoyu Island is an uninhabited island, just like many islands and reefs in the South China Sea. However, China has included it in the territory since ancient times (about the Southern Song Dynasty), and has visited it from time to time, but it has not stationed troops or immigrated to the Diaoyu Islands.

After World War II, due to Chiang Kai-shek's pro-Japanese stance, the Kuomintang government failed to take effective measures in time to recover the Diaoyu Islands (Roosevelt proposed to Chiang Kai-shek to return the entire Ryukyu Islands to China, but Chiang Kai-shek did not express his position because he wanted to use Japan's power in the civil war, so he did not want to offend the Japanese), and was later illegally handed over to Japanese jurisdiction by the United States in 72-everyone's attention: this happened before Kissinger's secret visit to China, so those who made friends with Nixon and Kissinger should wake up. The United States has never been a friend of China.