Xiao Yulong, 54, was responsible for ringing a bell to signal the end of an entrance exam in the province of Hunan.
However, he mistakenly rang the bell 4 minutes and 48 seconds early, reports Xinhua.
1,050 students were forced to stop writing and submit their tests as a result.
The government received numerous complaints from students and parents, which led to Xiao jailed for negligence - although he may not have to serve jail time as he was also given a one-year reprieve.
A court statement declared that Yulong's 'carelessness' resulted in 'adverse social impact'.
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