There is an alleged Chinese Curse "May you live in interesting times". According to Wikipedia no conclusive evidence of the origin of this phrase has ever been found... however it just about sums up December in the construction industry.
I think it can best be summed up by Donald Rumsfeld "There are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know.".
Current jobs have deadlines that are coming up before the break - everybody wants stuff finished before the holiday or first in the queue in the New Year. It is a fact that there are a few 'on the shelf' jobs which will resurrect themselves briefly before the break (just because they can) and cause resource chaos (two staff are off on break early). If every other year that I can remember since starting work is any indicator there will also be completely random exercises that appear from nowhere just to really throw the cat among the pigeons.
Add to the mix the variety of Christmas obligations that work throws up when project teams have parties, and the office party and so forth... season lightly with people getting colds and going off sick.
Interesting times... it certainly will be.