Parkinson’s law is a proverb coined by the British author Cyril Northcote Parkinson:
Work expands so as to fill the time available for its completion.
The law points out that people will often take up all the allotted time, if not more, to complete a task. It might be due to expanding the scope of the task due to the timeline, or procrastinating until the very last minute.
It’s those times where you spent weeks doing “research” and then finished doing the actual task on the very last day, or maybe a time where you went overboard on detail because you had a whole month when the task could have been handled in a few focused hours.
In each example the ‘work’ expanded to fill the time allotted.
This old Calvin Hobbes comic might surface a wry smile: