Leave for any length of time, especially in direct connection with holidays, is only granted in exceptional cases, on the basis of a well-founded written request. Such exceptions include doctors." appointments which cannot be moved, students having to stay at health resorts and family events, but not holiday or business trips by parents. Written application must be made at least four weeks prior to the date of travel. Parents are required to abide by these regulations in order for classes to be taught with minimum disruption.