This article on procrastination is a bit relevant. Not suggesting you are procrastinators, only it suggests to me that there is an internal clock that might signal a “best time to start” and then the determination to finish takes over. Wonder if this is a learned behaviour? As in you learned that starting and completion at a certain place in the assignment cycle got you better grades? Or if it’s a natural response of a good student to preform this way?

The author looks like an interesting person. For Laura G. maybe?

Data mining finds lessons about procrastination
Education by the Numbers
Column by JILL BARSHAY
June 15, 2015
http://hechingerreport.org/data-mining-finds-lessons-about-procrastination/