Why no discussion of the fact that people tend to wake up earlier as they age? A lot of professors are quite tired late in the day, and their lectures might not

Why no discussion of the fact that people tend to wake up earlier as they age? A lot of professors are quite tired late in the day, and their lectures might not be too terrific. It seems we should multiply two functions, one increasing and the other decreasing, to find the best time. And then put all classes at that single best hour. Or, well, you know ... stick with the working hours that basically every other adult has to deal with.