We currently have a few subjects (e.g. Philosophy of Religion and PSHE) which we rotate each half-term or term. At the moment to keep timetables correct and so registers correctly auto-default for staff we are adding/removing the lessons from the timetable for each set each half-term holiday. This is quite a fiddly & time-consuming job for admin staff - an easier solution would be to be able to hide/unhide the lessons from the set timetable each half term holiday. You can hide lessons on individual student timetables but this is not practical for a rotation that spans 4 year groups (600 students)! Or could you add a Transfer Timetable from one set to another to the Useful Timetable Tools?