The best time of the year regarding bank holidays in the UK is probably Christmas time, where people will get 3 public holidays almost in a week.
These bank holidays are Christmas-Day, Boxing Day and New Year’s Day.
This means that generally, people won’t work between Christmas and New Year’s Day, and London is probably the quietest and least populated time of the Year in London.
If we generally all understand what Christmas day and New Year’s Day refer to, it is usually not the case for newcomers.
According to the definition of The Oxford English Dictionary, Boxing Day is “the first week-day after Christmas Day, observed as a holiday on which postmen, errand boys, and servants of various kinds expect to receive a Christmas-box".
But what would be a Christmas box? In Britain and as well in Continental Europe, it was a custom for tradespeople to collect "Christmas boxes" of money or presents on the first weekday after Christmas as thanks for good service throughout the year. The Christmas boxes could also include the leftovers of Christmas dinner for servant and tradespeople to share.
Boxing Day was thus rooted in a tradition of caring and sharing.
Nowadays, one can say this nice tradition has turned into something much more mercantile: in the UK, it has become the first day of Winter Sale, lasting up to mid-January. It is generally the day of the year generating the highest revenue for merchants.
In my opinion, the week of Christmas is one of the best of the year to enjoy the British capital: lots of people have flown away from the center of London: consequently, you can enjoy shopping for bargains in a stress-less and serene way.
Something unusual in London, certainly not to be missed!