How we cite our quotes: (Chapter.Section.Paragraph) or (Chapter.Paragraph)
Quote #1
Coats and linen, however, are not merely values in general, but values of definite magnitude, and, following our assumption, the coat is worth twice as much of the 10 yards of linen. Why is there this difference in value? Because the linen contains only half as much labour as the coat, so that labour-power had to be expended twice as long to produce the second as to produce the first. (1.2.12)
To measure the value of a commodity—be it a coat or linen—you need to measure the quantity of time that went into producing it. This simple concept is known as the labor theory of value. Marx isn't the only proponent of the idea, but he's definitely one of the biggest. He places the concept of time right in the center of his economic views.
Quote #2
The fact that half a day's labour is necessary to keep the worker alive during 24 hours does not in any way prevent him from working a whole day. Therefore the value of labour-power, and the value which that labour-power valorizes in the labour-process, are two entirely different magnitudes; and this difference was what the capitalist had in mind when he was purchasing the labour-power [...] What was really decisive for him was the specific use-value which this commodity possesses of being a source not only of value, but of more value than it has itself. (7.2.22)
Seeing our time through the lens of Marx's theory brings new meaning to the workday. Now, we all have to keep ourselves alive. That's a worker's necessary labor time, which pays for the cost of him- or herself. But we're worked much more than that—and that's called surplus labor time. Imagine that half of your every minute at work is spent working for the cost to maintain your standard of living, and the other 30 seconds is work that goes into your employer's pocket. Does this sound like a fair deal?
Quote #3
If the Règlement organique of the Danubian Principalities was a positive expression of the appetite for surplus labour which every paragraph legalized, the English Factory Acts are the negative expression of the same appetite. These laws curb capital's drive towards a limitless draining away of labour-power by forcibly limiting the working day on the authority of the state, but a state ruled by capitalist and landlord. Apart from the daily more threatening advance of the working-class movement, the limiting of factory labour was dictated by the same necessity as forced the manuring of English fields with guano. The same blind desire for profit that in the one case exhausted the soil had in the other case seized hold of the vital force of the nation at its roots. Periodical epidemics speak as clearly on this point as the diminishing military standard of height in France and Germany. (10.2.6)
If your time is completely dominated by work, you have no time to rest, and your exhaustion would make you a less productive worker. Besides keeping the working class in check, Marx says the government passes laws to regulate the time of the workday so that reckless capitalists won't destroy their own workers through overwork. Rest is also necessary to keep the population a fit fighting force in case of war, after all.