The last Friday before Christmas apparently has been dubbed black / frantic/ mad/ black eye Friday (depending on which publications you look at) when the bars are packed with parties / post work meet ups and is more than a little busy for the emergency services. A quick news search reveals some sites declared last Friday black/ mad/ black eye Friday as well meaning they get to run the same piece twice so festive trebles all round! Most years I tend to avoid such parties, being slightly introverted and sharing nothing with my colleagues other than a confined space for part of the week.
I also enjoy having to order without having to deploy my sharp elbows and having chairs and tables available surrounded by people I enjoy being round and can hear talking. In other words I'm going out during January-land.