Earlier quoted context omitted.
I actually liked the one time zone system in China when I lived there. It made scheduling work across different cities a little more convenient, and I didn't mind that the sunrise/sunset didn't always exactly line up to what I am accustomed to.
I can understand not exactly lining up, but considering how large the country is and how Beijing is so far east it seems like people in the west would have the sun rise at 2:00 or the sunsetting at 14:00. I don't know this for certain I'm just curious how not lined up it can get at the most extremes.
But it would definitely screw up cultural references, e.g.: a "5pm tea" then can only be understood with a broader cultural context: "UK, 5pm is late in the 2nd half of the working day for them".