The gloomiest week,
Time when everybody leaves,
I think airfares typically ramp up for a week or so after the mid-point of December, so this - the second week of the month - is traditionally when most expats quit Beijing for their Christmas break. It is miserable to be one of the few left behind. I think I'm going to treat myself to a holiday this year too; but maybe not until the flights get cheaper again on Christmas Day.