I've just been to my local village supermarket, and asked one of the girls there when they were closed over Christmas. "Christmas Day and Boxing Day" she said. I then caused immense confusion by asking her if by "Boxing Day" she meant the day after Christmas (ie the Saturday), or the official bank holiday, which is of course on the Monday this year. "Er..." came the answer.
Five minutes later there were about half a dozen of them all gathered round, trying to work out whether it was the Saturday or the Monday that they were closed. The concept that the day after Christmas might not be the official Boxing Day holiday seemed to be a radical concept...
Eventually the Manager was summoned, and clarification obtained: they are closed on the Saturday, and open on the Monday. All is now clear!