Why is it important to meet a deadline?There is an empirical Parkinson's law: work takes all the time it takes.
How it works:Work that is allotted more time than necessary will be completed, but some of the time goes incomprehensibly elsewhere.
Sound familiar?
In that case, you can use
Parkinson's Law:Allocate as much time to work as you need. Don't move the deadline! Otherwise, it won't work, because you'll know that the actual deadline isn't soon enough. A more effective way is to shorten your time on a task by doing something useful before it.