I think you're combining two subjects that need to treated separately: daylight savings (which, you're correct, wasn't implemented until the 1980s) and the unified time zone centered near Beijing (which was implemented in 1949). Briefly, there was also a "Lhasa Time" in Tibet and "Urumqi Time" in Xinjiang. The first was ceased, and the second eventually recognized (again, in the 1980s). At 11:50 AM -0800 2/11/08, Paul Eggert wrote:
From: Thomas S. Mullaney [mailto:tsmullaney@stanford.edu] Sent: Friday, February 08, 2008 3:55
This is a project I started thinking about this past summer - a fascinating topic, no?
Yes, quite addictive....
Perhaps there is a confusion between two different topics here. The tz database is mostly concerned with the actual clock settings; it doesn't record (except in comments) whether the time zone is called "Beijing Time" or "Beiping Time" or something else. Historically, Beijing Time (under whatever name) covered just part of the territory of China; the question the tz database is concerned with is when this was expanded to include the whole country. You can find a map of the old "Beiping Time" (perhaps "Chungyuan Time" is a better name) zone in <http://en.wikipedia.org/wiki/Time_in_China>. What's missing is when that time zone expanded to included the whole country.
I just now checked Google News for western news sources that talk about China's single time zone, and couldn't find anything before 1986 talking about China being in one time zone. (That article was: Jim Mann, "A clumsy embrace for another western custom: China on daylight time--sort of", Los Angeles Times, 1986-05-05. By the way, this article confirms the tz database's data claiming that China began observing daylight saving time in 1986.)
Obviously this simple search isn't conclusive, as it doesn't include reliable Chinese sources; still, it is not at all clear from the data mentioned above that China switched to a single time zone in 1949.
-- --- Thomas S. Mullaney Assistant Professor Modern Chinese History Department of History Stanford University 450 Serra Mall, Bld 200 Stanford, CA 94305-2024 T (650) 736-8386 F (650) 725-0597