First of all, for some reason there is a Vietnamese timezone which got sandwiched between time zone of China in the backzone file, I think that should be reordered for better clarity Second, the historical timezone data for those China zones seems to be incorrect. The transition to GMT+8 date given there for these zones were 1980 which also contradict the file description that they do not disagree with normal zone after 1970. According to sources that have also been cited in the asia file, except Xinjiang and Tibet, they should have adopted the Beijing Time from around 1949/1950 depends on exactly when each of those cities were taken over by the communist army. And they should also follow the DST setting of Asia/Shanghai after that point of time. In addition, http://gaz.ncl.edu.tw/detail.jsp?sysid=E1091792 the document from Chongqing Nationalist government say in year 1945 all of China should adopt summer time due to the war (not sure whether it continued after WWII ends)(Probably only enforced in area under their rule at the time?) The Asia/Harbin's 1932 and 1940 entry should also be incorrect. As per sources recorded at https://wiki.suikawiki.org/n/%E6%BA%80%E5%B7%9E%E5%9B%BD%E3%81%AE%E6%A8%99%E... , in 1932 Harbin should have adopted UTC+8:00 instead of data currently listed in the tz database according to official announcement from Manchuko. And they should have adopted GMT+9 in 1937 January 1st according to official announcement at the time being cited on the webpage.