tz database holds that People's Republic of China maintained 5 different time zones between the foundation of the PRC in 1949 and May 1980, when the uniform Beijing timezone (GMT + 8h) was introduced. Various sources claim that this unified country-wide timezone was already introduced in 1949 or early 1950: Several TZ mailing list entries, e.g. 10/16/2010 by Jonathan.Hassid@uts.edu.au who writes: "The government in Chengdu (capital of Sichuan province) announced the switch (from "Shulong" (Gansu/Sichuan) time) to Beijing time on 27 Dec. 1949. The rest of the country followed "in early 1950" (dates unspecified), and as I mentioned in my last email, "by the beginning of 1950, within a few months after establishing the country, the entire country except for Xinjiang and Tibet was all using the Beijing Time standard." Paul Eckert tried to get an answer from historian Thomas S Mullaney in a correspondence in February 2008, but the question whether China introduced the unified timezone in 1949 or 1980 remained unanswered by Mullaney (he is currently on leave from Stanford and cannot be contacted). The Wikipedia articles 'Time in China' http://en.wikipedia.org/wiki/Time_in_China and 'Historical time zones of China' http://en.wikipedia.org/wiki/Historical_time_zones_of_China hold that the unified timezone was introduced in 1949. They say: "These time zones were no longer in effective use after 1949, in the Chinese Civil War when the People's Republic of China was established on mainland China. The People's Republic of China uses a single time zone (GMT+8) for the whole country," and "After the Chinese Civil War in 1949, the People's Republic of China established one single time zone (UTC+8) for the entirety of its claimed territories, " I could not identify the source reference for this claim by the Wikipedia authors. I tried to contact one of them, User:Alanmak by various means without success. He seemed to me the main contributor regarding China TZ history. This seems to be a relevant source: Guo, Qingsheng (2003) "Beijing Time at the Beginning of PRC", China Historical Materials of Science and Technology 24(1) It is an article in Chinese (it can be purchased online), and I do not know a translator whom I would trust with translation of such technical or historical detail. It seems to me that the only source claiming the continuation of 5 time zones for China is the International Atlas by Shanks and Pottenger. The overall work of these authors is extremely valuable, but they do not give a source for their China information. Paul Eckert says in tz/asia file: # From Paul Eggert (2008-06-30): # There seems to be a good chance China switched to a single time zone in 1949 # rather than in 1980 as Shanks & Pottenger have it, but we don't have a # reliable documentary source saying so yet, so for now we still go with # Shanks & Pottenger. I agree with Paul's opinion and decision, but find it not acceptable to remain at this degree of uncertainty or such a large area, long time period of 31 years and such a large population of hundreds of millions of people: We do NOT reliably know which timezone there was in January 1980 in large cities like Chengdu or Chongqing. I appeal to those readers of the mailing list capable of reading Chinese / mandarin to look for sources which could - document that multiple timezones where indeed maintained before May 1980 (e.g. railway or airline time tables of that period), - document the transition to a unified zone in May 1980 (legal text, newspaper articles mentioning the time change) - document the government decision for a unified timezone in 1949 My gut feeling is that the unified timezone was introduced in 1949, and that Shanks got it wrong. We need documents to establish that.