Key Arguments

• The necessary part of the working day is determined by the time required to produce the worker's subsistence
• The surplus labor time can vary (e.g., extending the day to 7, 9, or 12 hours) without altering the necessary labor time
• The total length of the working day is the sum of necessary labor plus variable surplus labor

Source Quotes

It would indicate that the two constituent parts of the working day, necessary labour-time and surplus labour-time, were equal in extent, but not how long each of these two constituent parts was. The working day is thus not a constant, but a variable quantity. One of its parts, certainly, is determined by the labour-time required for the reproduction of the labour-power of the worker himself.

The working day is thus not a constant, but a variable quantity. One of its parts, certainly, is determined by the labour-time required for the reproduction of the labour-power of the worker himself. But its total amount varies with the duration of the surplus labour.

One of its parts, certainly, is determined by the labour-time required for the reproduction of the labour-power of the worker himself. But its total amount varies with the duration of the surplus labour. The working day is therefore capable of being determined, but in and for itself indeterminate.

But its total amount varies with the duration of the surplus labour. The working day is therefore capable of being determined, but in and for itself indeterminate. Although the working day is not a fixed but a fluid quantity, it can, on the other hand, vary only within certain limits.

Key Concepts

• The working day is thus not a constant, but a variable quantity.
• determined by the labour-time required for the reproduction of the labour-power
• its total amount varies with the duration of the surplus labour
• capable of being determined, but in and for itself indeterminate

Context

Marx analyzing the structural composition of the working day in terms of value creation.