[jlg23]

As long I am not working the same hours as people in the far east of China, I would not really care about what the clock reads at sunset: I'd just get up around sunrise at n o'clock, spend my hours at work and finally go to bed at m o clock. The only difference between n=6, m=22 or n=22,m=14 is habituation. We're used to the former.

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".