The establishment of a normal working day is the result of centuries of struggle between capitalist and labourer. The history of this struggle shows two opposed tendencies.
 Karl Marx, Das Kapital (1867). copy citation

add
Author Karl Marx
Source Das Kapital
Topic struggle history
Date 1867
Language English
Reference
Note Translated by Samuel Moore and Edward Aveling
Weblink https://www.marxists.org/archive/marx/works/download/pdf/Capital-Volume-...

Context

“But looking at things as a whole, all this does not, indeed, depend on the good or ill will of the individual capitalist. Free competition brings out the inherent laws of capitalist production, in the shape of external coercive laws having power over every individual capitalist.82
The establishment of a normal working day is the result of centuries of struggle between capitalist and labourer. The history of this struggle shows two opposed tendencies. Compare, e.g., the English factory legislation of our time with the English labour Statutes from the 14th century to well into the middle of the 18th.83 Whilst the modern Factory Acts compulsorily shortened the working day, the earlier statutes tried to lengthen it by compulsion.” source