I work in a rapidly-growing International school in China. As each year passes, we have more students which adds stresses on our limited resources of learning spaces and teachers. Thrown into the mix are frequent requests from specialist teachers and some class teachers to have longer blocks of time with students than our current 40 minute lesson periods. I have launched a scheduling committee at my school with a cross section of teachers involved in researching the options available to provide more efficient and better-quality learning experiences for the students. The research seems to suggest that it is difficult to categorically link timetabling decisions to improved student learning because the issue is more how teachers spend their time than how long they spend on a particular area. However, even without a direct correlation to student learning improvement there are definitely logistical, and financial implications to more efficient scheduling. I would like advice from anyone who has experimented with differing lengths of period in their schedules, including the more challenging notion of a non-standard timetable with certain specialist classes being longer or shorter than others. In short I would like to be able to reach a satisfactory answer to the following question? How long should lessons be to maximise efficiency and impact positively on students and teachers?