Timelines

I know in teaching when I gave students a month to finish a project, they procrastinated for three weeks before starting. I would have been better off giving the students one week to completion. After giving students my rationale, they came to accept my logic and in doing so, we alleviated three weeks of anxiety in the lead up to the completion date.

What do you put off or extend a timeline on that can be completed much quicker when you give yourself some more rigid, immediate timelines?