Patience is, as has often been said, a virtue.
I was just thinking about patience this way?
What is more important: to get what you want, or to get what you want by some deadline?
Deadlines appear in our lives, both imposed by others and by ourselves. Most deadlines have loopholes. Especially deadlines we set for ourselves.
"I have to finish my chapter by the end of the week." Well, that's a great plan, and I encourage you to try. You have a better chance of accomplishing that goal if you have a more detailed plan than simply to finish. If you have such a plan, it probably breaks the larger project up: "I have to write a section on topic A, and I have to write a section on topic B." Then you have two tasks (that need to be finished by the deadline); each task is less imposing.
But suppose you reach the end of the week without having finished, what do you do then?
It is to be hoped that you keep on writing, and you continue to strive to finish the chapter, even though your deadline has passed.
There is no doubt that there are deadlines in life that are undebatable, unextendable and absolutely final. But most are not--even when imposed by an outside source--like a university. Often deadlines can be appealed for an extension. I'm not here promoting trying to extend your work. I strongly believe in finishing before the deadline, so that it's not even an issue. My point about patience is that it helps us prioritize the ultimate goal (finishing the dissertation, for example) over the lesser goal (e.g., finishing this semester).