I’ll concede that point. And I’d like to add that the modern clocks as we know them are also a very modern invention. Farmers in Medieval Europe certainly did not have a device in their homes which chimed the hour with regular and exact precision. The closest equivalent they would have had were clock towers, starting about the fourteenth century, funded by local merchants guilds. It was these same merchants who were in the habit of keeping a human skull in their offices as a memento mori, reminding them to make good use of their time, as each chime of the clock brought them one hour closer to death. There were no time clocks which a serf could use to punch in or out of work for the day, no payroll and accounting department in the employ of the local lord to keep track of all hours worked, etc. Time was not a grid against work could be measured because the work was the measure itself.