There can be considerable productivity gained, for very short windows of time. It's all "tortoise and the hare". If you have something due at 7AM, sprint. If it

There can be considerable productivity gained, for very short windows of time. It's all "tortoise and the hare". If you have something due at 7AM, sprint. If it's due in three months, pace yourself and optimize average productivity, which usually means balancing working hours against sleep, exercise, relaxation, socialization, and food.