Engineering360: "A System for Detecting Driver Drowsiness"

Interesting article. It would be nice to know when the 36 hours started at.

If it was 12 noon on Monday to 12 noon on Tuesday, followed by 12 more hours would put the test at 12 midnight and one could expect a certain type of measurement.

If it was 12 midnight on Monday to 12 midnight on Tuesday, followed by 12 more hours, that would put the test at 12 noon and one might expect a different type of measurement.