Private schools started adopting two-week October half term holidays when they started the autumn term earlier and earlier as the end of the summer term crept earlier and earlier because the dates of the public exams were doing the same, and it proved impossible to do any meaningful educative stuff with those who had taken them, which could be 40% of the pupils in a 13-18 school. I taught in such an establishment (boarding) in the 1980s and no matter how hard we tried, they would not take 'introduction to A levels' classes seriously and just spent their time out in the fields smoking, getting drunk or worse; so we sent them home. By the 1990s the autumn term was now stretching from the beginning of September nearly to Christmas, which was nearly half of the teaching days in an academic year and far too long for people (staff or students) to keep on the boil, so the two-week break was actually beneficial for everyone.