Did you know from 1912 until 1949, China did have 5 time zones: Kunlun (UTC +05:30), Sinkiang-Tibet (UTC +06:00), Kansu-Szechwan (UTC + 07:00, Chungyuan (UTC +08:00). and Changpai (UTC +8:30).
In 1949, Communist Party Chairman, Mao Zedong, decided that all of China was to use Beijing Time.
China is approximately 3,100 miles wide from east to west. It is 3,400 miles long from North to south.
Time in China ........
www.wikipedia.org/wiki/Time_in_China#
"Daylight saving time ....
www.wikipedia.org/wiki/Daylight_saving_time ..... was observed in China from 1945 to 1948, and from 1986 to 1991."