Parkinson's law states that "work expands so as to fill the time available for its completion." It is also formulated as: "The amount of time that one has to perform a task is the amount of time it will take to complete the task." I guess there's no need for much explanation here. We've all been there.
So what's my natural response to this? I leave the work to the last minute, cause this way it'll take less time to do. Some people call it procrastination. I just call it being efficient. (And really stressed sometimes).