Question: When did was the cease fire of the event that started when the Kwantung Army of the Empire of Japan invaded Manchuria?

Context paragraphs:
Northeast National Salvation Society: The Northeast National Salvation Society was an organization formed by exiles from Manchuria, (the Northeast) in order to put pressure on the Chinese government of Chiang Kai-shek to end its policy of non resistance to the Empire of Japan that had invaded Manchuria after the Mukden Incident and to assist the volunteer armies, especially the Northeast People's Anti-Japanese Volunteer Army in Liaoning, led by Tang Juwu.  One of its chief supporters was Zhang Xueliang who privately supported this resistance, despite his public obedience to the government policy of non resistance.  Zhang was not publicly associated with the Society and never held office in it, but provided funds and allowed it to use his name when communicating with volunteer armies.

Tientsin Incident (1931): The Tientsin incident of 1931 was the operation planned by the Kwantung Army of the Empire of Japan to place Puyi on the throne of the Japanese-controlled Manchuria.  The plan, orchestrated by Colonel Kenji Doihara and Colonel Itagaki Seishiro was successful, and Pu Yi was enthroned as "Emperor Datong" of Manchukuo the following year.

Jordan–Israel Mixed Armistice Commission: Hashemite Kingdom of Jordan/Israel Mixed Armistice Commission (HKJI MAC) was the United Nations organisation of observers which dealt with complaints from Jordan and Israel to maintain the fragile cease fire along the demarcation line (Green Line) between Israel and Jordan.  At the closing of the 1948 Arab-Israeli War, on 3 April 1949, the Hashemite Kingdom of Jordan signed a truce with Israel called the 1949 Armistice Agreements.  The United Nations Truce Supervision Organisation posted Military Observers as part of the Mixed Armistice Commissions (MACs) to Observe the truce on the Cease fire line and to liaise with the Israeli and Jordanian local area commanders.  While the 1948 war was concluded with the 1949 Armistice Agreements it has not marked the end of the Arab–Israeli conflict.  The HKJ/IMAC was the organisation which monitored the Jordan/Israel truce agreement, the HJK/IMAC Headquarters was located in Jerusalem close to the Green Line and, through close liaison with the UNTSO headquarters in Government House, Jerusalem, was charged with supervising the truce, investigating border incidents, and taking remedial action to prevent the recurrence of such incidents along the Jordan/Israel Green Line.

Huanggutun incident: The Huanggutun Incident (), or Zhang Zuolin Explosion Death Incident (Japanese: 張作霖爆殺事件 , Hepburn: Chosakurin bakusatsu jiken ) , was an assassination plotted and committed on June 4, 1928, by the Japanese Kwantung Army that targeted Fengtian warlord Zhang Zuolin.  It took place at the Huanggutun Railway Station near Shenyang, where Zhang's personal train was destroyed by a railside explosion.  This incident was concealed in Japan at the time and was referred only as "A Certain Important Incident in Manchuria" (満州某重大事件 , Manshu bou judai jiken ) .

Japanese invasion of Manchuria: The Japanese invasion of Manchuria began on 18 September 1931, when the Kwantung Army of the Empire of Japan invaded Manchuria immediately following the Mukden Incident.  The Japanese established the puppet state of Manchukuo, and their occupation lasted until Soviet Union and Mongolia launched the Manchurian Strategic Offensive Operation in 1945.

Soviet invasion of Manchuria: The Soviet invasion of Manchuria, also known as the Manchurian Strategic Offensive Operation ("Манчжурская стратегическая наступательная операция" , lit.  "Manchzhurskaya Strategicheskaya Nastupatelnaya Operaciya") or simply the Manchurian Operation ("Маньчжурская операция"), began on 9 August 1945 with the Soviet invasion of the Japanese puppet state of Manchukuo.  It was the last campaign of the Second World War, and the largest of the 1945 Soviet–Japanese War which resumed hostilities between the Union of Soviet Socialist Republics and the Empire of Japan after almost six years of peace.  Soviet gains on the continent were Manchukuo, Mengjiang (Inner Mongolia) and northern Korea.  The Soviet entry into the war and the defeat of the Kwantung Army was a significant factor in the Japanese government's decision to surrender unconditionally, as it made apparent the Soviet Union would no longer be willing to act as a third party in negotiating an end to hostilities on conditional terms.

Pacification of Manchukuo: The Pacification of Manchukuo was a Japanese anti-insurgency campaign during the Second Sino-Japanese War to suppress any armed resistance to the newly established puppet state of Manchukuo from various anti-Japanese volunteer armies in occupied Manchuria and later the Communist Northeast Anti-Japanese United Army.  The operations were carried out by the Imperial Japanese Kwantung Army and the collaborationist forces of the Manchukuo government from March 1932 until 1942, and resulted in a Japanese victory.

Kwantung Army: The Kwantung Army was an army group of the Imperial Japanese Army in the first half of the 20th century.  It became the largest and most prestigious command in the IJA.  Many of its personnel, such as Chiefs of staff Seishirō Itagaki and Hideki Tōjō were promoted to high positions in both the military and civil government in the Empire of Japan and it was largely responsible for the creation of the Japanese-dominated Empire of Manchukuo.  In August 1945, the army group, only around 713,000 (from a previous total of 1,320,000) men at the time, was defeated by and surrendered to Soviet troops as a result of the Manchurian Strategic Offensive Operation.

Tanggu Truce: The Tanggu Truce, sometimes called the Tangku Truce (Japanese: 塘沽協定 , Hepburn: Tōko kyōtei ) , was a cease-fire signed between Republic of China and Empire of Japan in Tanggu District, Tianjin on May 31, 1933, formally ending the Japanese invasion of Manchuria which had begun two years earlier.

Zhang Zuolin: Zhang Zuolin () (1875–1928) was the warlord of Manchuria from 1916-28, during the Warlord Era in China.  He successfully invaded China proper in October 1924 in the Second Zhili-Fengtian War.  He gained control of Peking, including China's internationally recognized government, in April 1926.  The economy of Manchuria, the basis of Zhang's power, was overtaxed by his adventurism and collapsed in the winter of 1927-28.  He was defeated by the Nationalists under Chiang Kai-shek in May 1928.  He was killed by a bomb planted by a Japanese Kwantung Army officer on 4 June 1928.  Although Zhang had been Japan's proxy in China, Japanese militarists were infuriated by his failure to stop the advance of the Nationalists.

Supporting paragraphs: Tanggu Truce Japanese invasion of Manchuria
Answer: May 31, 1933