After reading about human beings' natural tendency to "anchor" on things like the next 100-point ELO rating, that probably a better way of doing things would be

After reading about human beings' natural tendency to "anchor" on things like the next 100-point ELO rating, that probably a better way of doing things would be to say it was due at midnight, but there was a 10-minute grace period. people naturally will tend to aim for midnight, regardless of whether it's a hard deadline or not. IOW, my professor's insight that there had to be a hard deadline somewhere was correct. But he missed the fact that not all hard deadlines are equal: a hard deadline that is 10 minutes past a natural "anchor" is much easier for anchor-prone humans to meet than a hard deadline right on a natural "anchor". Which is a bit strange, because the official university policy with regard to scheduling actually already took into account this natural anchoring: It was official policy that if a schedule said 10:00-11:00, the class was actually 10:10-11:00. The idea being that it's much easer for the "hard end" of a class to be at 11:00 than 10:50.