Tiffanie Wen at the BBC writing about Parkinson's law:
It is a commonplace observation that work expands so as to fill the time available for its completion.
Cyril Northcote Parkinson was a British naval historian and author who (in an essay for The Economist) noted:
Although the number of navy ships decreased by two thirds, and personnel by a third, between 1914 and 1928, the number of bureaucrats had still ballooned by almost 6% a year. There were fewer people and less work to manage – but management was still expanding.
The takeaway from the article seems to be that if you want to improve your time management we should be giving ourselves tighter deadlines, but not so tight that we neglect other duties.
It reminds me of the saying:
If you want something done, give it to a busy person.