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How quickly did Japan occupy all of Manchuria after the Mukden Incident?

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Map of eastern Asia highlighting Manchuria in northeastern China, which includes the provinces of Heilongjiang, Jilin, Liaoning, and part of the Inner Mongolia Autonomous Region. The highlighted area borders Russia, Mongolia, and North Korea. — Manchuria The historical region of Manchuria shown with the boundaries of the modern-day Chinese provinces in its place as well as the portion of the Inner Mongolia Autonomous Region that is often considered part of Manchuria.

Following the Mukden Incident on September 18, 1931, the Japanese military moved quickly to seize control of the region. While the Kwantung Army faced little resistance due to the Chinese government's policy of nonresistance, estimates regarding the timeline of the full occupation vary slightly among historical accounts.

Some records indicate that Japanese forces had spread throughout Manchuria within three months of the initial attack. Other accounts note that the Japanese were able to occupy the entirety of the region within five months. By March 1932, the occupation was solidified with the formal establishment of the puppet state of Manchukuo.123