411A
The problem is, with the way many rostering petterns seem to be developing, that planning your rest is just about impossible.
V. early flight one day, v.early standby the next, suddenly change to a night trip crewing in at the same time as your body says it's time for bed.
Why should anyone have to do an exam containing all that stuff about circadian rhythms if the planners don't take a blind bit of notice?
All company planning staff (schedule writers, rostering/crewing staff and Ops staff) should have to pass the Human Performance exam before getting the job.