Dear Paul, Thanks for your email. The dating of "Beijing Time" is a little tricky, but thanks to Guo Qingsheng, a scholar and engineer at the Chinese Academy of Sciences Shaanxi Observatory, we know that the implementation of Beijing Time must have come after September 27, 1949 - the date on which the official name of Beiping (Northern Peace) was changed to Beijing (Northern Capital) - and some time before October 7 - the date of the earliest source which Guo has found containing the term "Beijing Time." This is a project I started thinking about this past summer - a fascinating topic, no? Sincerely, Tom Mullaney
In a book review in today's issue of _Science_ you reported that the Chinese government in 1949 opted to observe one time zone. This caught my interest because I help maintain the tz database, which records histories of time zone and daylight saving changes all over the world. The tz database is used by computer clocks all over the world, including what I expect are millions of clocks in China, so I'd like to get the details right.
Here's the problem: the tz database, following Shanks & Pottenger (2003), records that the China switched to a single time zone on May 1, 1980, not in 1949. Since you are a historian of China I expect that you have a lot better sources than we do. Can you please mention the sources for the claim that the clocks changed in 1949 rather than in 1980?
Thanks for any info you can provide. I'll CC: this message to the tz database mailing list, to give them a heads-up on this query.
-- Paul Eggert, UCLA Computer Science Dept.
References:
Thomas S. Mullaney, Change of time over changing time. Science 319 (5864), 729 (2008-02-08), DOI: 10.1126/science.1152851, <http://www.sciencemag.org/cgi/content/full/319/5864/729a>.
Paul Eggert & Arthur David Olson, Sources for time zone and daylight saving time data <http://www.twinsun.com/tz/tz-link.htm> (2007-12-31); also see <http://en.wikipedia.org/wiki/Zoneinfo>.
Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition). San Diego: ACS Publications, Inc. (2003).
-- --- 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