“Work expands so as to fill the time available for its completion”. – Cyril Northcote Parkinson wrote this as part of the first sentence of a humorous essay published in The Economist in 1955. In time, however, the first-referenced meaning of the phrase has sprouted several depictions, the most well known spin off phrase being:
If you wait until the last minute, it only takes a minute to do.
Basically he is saying that, if a person allows them-self one hour to complete a certain task, that is how long it will take. Therefor in the same breath, if that person gave them-self 45 minutes for the same task, they would complete that exact task in that time.
If you have ever tried this as part of your working day or merely as an experiment then you will understand that this law is absolutely true. How many times have you given yourself 2 hours to complete an essay that you could have very easily written in 1? By giving yourself a strict deadline and sticking to it, you will realise how much more efficiently you will work. After all procrastination makes easy things hard, and hard things harder.