How did people set or time working hours before the adoption of mechanical clocks? Did mechanical clocks led to increased productivity for this reason?

The widespread adoption of mechanical clocks in 16th-18th century Europe, particularly England, signaled a shift in work from being task oriented to time oriented, where labor shifted from being, “the day’s tasks, disclosed by themselves and the logic of need” to “work organized by regular, coordinating time-disciplines." Put differently, the progression from the natural and nonuniform where work and leisure blurred, to, paraphrasing EP Thompson, an “unnatural life tyrannized by the clock and timed labour.” This transition was by no means smooth as Thompson's works on both time and capitalism shows, to say nothing of the language of that quote! Although perhaps anecdotally, as this claim has yet to be taken up by historians, Walter Benjamin in On The Concept of History, speaks to an example from the July Revolution in which the clock towers were fired upon by those on the barricades where he quotes the poet Jospeh Méry.

Qui le croirait! on dit, Who would've thought! As though

qu'irrités contre l'heure Angered by time’s way

De nouveaux Josués The new Joshuas

au pied de chaque tour, Beneath each tower, they say

Tiraient sur les cadrans Fired at the dials

pour arrêter le jour. To stop the day.

If nothing else, it serves to remind us of the tense process of changing temporal orders.

The shift in time from something privately organized around one's tasks, to something socially coherent led to an expansion of person timekeeping devices, namely wall clocks and pocketwatches (if you had the means). This was for two main reasons. First, the obvious, you now needed to be on time for the work day. In the task-orientation of labor, starting later meant finishing later or having to put work off until the next day. There was no set time that the blacksmith had to start his day, nor a set time the farmer had to be out in the field. With the rise of time-orientation and capitalism work and leisure time were sharply divided, thus making tardiness a fireable offense. Secondly the expansion of personal timekeeping devices meant that no one single authority could claim the time. As David Landes notes,

"The employer had an interest in getting a full day's work for the wages he paid, and the worker in giving no more time than he was paid for. The question inevitably arose: how did, indeed how could, the worker know whether the bell time was honest time? How could he trust even the municipal bells when the town council was dominated by representatives of the employers"

The expansion of personal timekeepers had the effect of checking the perversion of time by those who stood to profit off of it, as well as setting the framework of the timed work day. The hour, not the sun, came to control when it was quittin' time. Further, with this routinized clock-time, workers were able to organize and make demands on when the workday began how long it would be. This double edged sword as Landes writes, "gave the employer bounds to fill and the worker bounds to work."

So this leads us to the question of productivity. As Thompson, Landes, and others (Glennie & Thift, Bertucci, McCrossen) note , the rise of clock and time-discipline is integrally linked to the rise and expansion of industrial global capitalism, by which I mean productivity. Was this time-discipline a cause for this increase in production, or was it an effect? Does technology drive economy, or does economy drive technology? On this, I side with Paola Bertucci, who in her study of the mechanical arts in ancient regime France agrees with Landes' view that clocks and time-orientation were a vital tool in building the capitalist system. She writes, "A ruling class able to see the [spirit] at work in machines and other practical inventions would readily understand the role that [clockmakers] could play in guiding France toward a golden age of imperial and commercial expansion." Further, work done on colonial plantations by Sidney Mintz stresses the need that plantation owners had for factorylike time-discipline in order to reap their greatest profits.

While I'm hesitant to go as far as solely attributing capitalism's expansion to time-orientation and clocks, there is strong evidence for it both as an engine for increasing profits as well as for driving force of class consciousness