Cambridge takes every care when constructing a timetable to try to avoid setting examinations on major religious and national holidays and also to try to avoid setting examinations in such a way that will cause timetable clashes. However, this is a very complex task with many constraints and it is not possible to produce a timetable that suits all 160 countries we work with.
We publish a provisional timetable for the June and November examination series, so that centres can inform us of any major difficulties the timetable may present. As changing the time of one exam for one customer can have a potentially major impact on many of our other customers, we only tend to make changes to accommodate global religious holidays or other highly significant events that impact a very large number of our entries. Sometimes this means that we cannot avoid timetabling exams on days that may be national holidays for a small number of our customers.
Once we have considered all comments received we then publish the final version of the timetables. After the final timetables have been published, we are unable to accept any requests to change exam dates.