text: When the hand of God strikes, nudging a major GCSE exam into the path of an England World Cup match, it can be a teachers' worst nightmare.
  A clash with the Muslim month of fasting may also cause concern in some schools wanting their pupils to do their best.
  And as exam timetabling is something of a long game, there can be no last-minute changes to scheduling to take into account a major football fixture.
  With so much hype over world sporting events such as the Olympics or the World Cup, most people will want to watch, says former exams doctor George Turnbull.
  "With the best will in the world, it is very difficult to talk young people down from taking time out of their revision to watch such events, and staying up late is not the best way to prepare for examinations," says the former adviser for exams regulator Ofqual.
  "Of course young people should be preparing long before hand, but we all know that it doesn't always work like that
  The exam itself should be the major event because it has so much potential to affect the young person's life chances," he adds.
  The public exams timetable is drawn up by the Joint Council for Qualifications at least 18 months in advance of the exams themselves, following consultations with a wide range of stakeholders including religious groups, schools and colleges.
  And because of the narrow window in which exam boards can hold examinations and get them marked, they are always in a fixed period of six weeks in the education calendar.
  The JCQ has reiterated that there were only minimal changes carried out to the draft timetable for 2016  before it was published.
  "In such a large, complex system where there is a large number of candidates taking examinations and a diverse range of subjects available, it is not always possible to meet each and every request," it says.
  "Exam boards will always aim to be as fair as possible to all.
  "If a small change can be made for any one group that does not impact negatively on most students, it will, quite rightly, be considered - but these are made before the timetable is published."
  And even as that timetable is drawn up, there is very little room for manoeuvre, says Andrew Harland, chief executive of the Exam Officers' Association.
  He cites the example of one local authority that complained, unsuccessfully, their students were going to have to sit a maths exam during their half-term holiday.
  Exam boards have to get GCSE papers marked in time for schools and colleges to decide places on sixth-form courses, he explains.
  Equally, A-level papers need to be graded so universities can confirm places to potential undergraduates.
  In recent years, the exam season has moved from June to July to late May to June, in part, to enable boards to get enough markers.
  Mr Harland says exams used to run up to the end of term, when people were going on holiday.
  "The days of markers taking a bundle of papers down to a cottage in Cornwall are over, as marking has moved online," he says.
  There may be a few cases where students taking unusual sets of subjects may have exam clashes, Mr Harland says.
  This can mean they have to take a paper at a later time of day and will thus need supervision so the integrity of the examination paper is maintained.
  But the major change in exam timetabling in recent years has been to what he describes as a "one-hit summer exam system" in which all exams are taken at the end of a two-year period and retakes have been discouraged.
  This, he argues, has put even more pressure on exam boards to get timetabling right first time.
target: As it emerges that GCSE and A-level exam timetables have been drawn up to minimise clashes with the Muslim holy month of Ramadan, we take a look at what influences and restricts scheduling.