I work in education in London - I started my holiday at lunch time on Wednesday 20th, go back to work on Monday 8th January. Theoretically I could have worked the rest of the week of the 20th (the building is closed over the following two weeks), in practice I used some of my leave time. The public holidays here are 25th-6th December (with the following days off if they fall on the weekend) and January 1st, or the monday if it's a weekend day.