sense of time in people with no means for time measurement

Question

How did early, e.g. ancient to early medieval times, people have a sense of time, i.e. an hour, with no clocks around?

I am aware that mechanisms for time measurement existed, sundials, water clocks, candle clocks, etc., but I assume they were not affordable to everyone. Therefore, my question is directed primarily towards common people. As an example, consider a number of guardsmen assigned to a relatively isolated watchtower, who are assigned to watch shifts. I imagine that by day they could orient themselves by the sun, by night they could use the moon and stars, but what when there are no celestial objects to reference? Furthermore, this approach fails to take into account the variability of celestial movements due to the change of seasons. Finally, the concept of an "hour" is very old, ancient civilizations divided the day for sunrise to sunset into 12 parts, how does one intuitively divide such a large timespan into units, which are rather large by themselves? Was some "chief" assigned the duty to anounce/keep track of time? It appears logical to me that the passage of time was not so crucial to people then as it is now, but I'm baffled by the huge impact of relativity in my above considerations, assuming they are at least partially correct, of course. Imagine what an hour would feel like to a worker in the fields and to his overseer and how the day would be divided if either of them were prompted to announce the passage of one hour.

Answer 1

Most common people had no great need to know the time to any meaningful precision. Those who needed the time either relied on the sun, or relied on the community's effort at time keeping (more on this later).

Generally speaking, especially for people in remote regions, the sky was their clock. As you noted in your answer, they could glance up at the sky and guess at the approximate time. For most of the population, that suffice for all practical purposes. To farmers and the like, waking at dawn and going home at dusk did not require precise knowledge of the hours worked.

In trade centres such as cities, more precise time telling was necessary to regulate business hours. While you are probably correct to think that contemporary time keeping devices were unaffordable, that is not as big a barrier as you might think. After all, an individual commoner need not try to own and maintain a timekeeping device all on their own: in settlements, that was taken care of as a communal task/government service.

In Medieval Europe, the church divided the day into eight canonical hours. The common people would have been able to track time via the church's ringing of bells for each Divine Offices. In between, a sundial on the local church's wall would have been common. The British Sundial Society for instance tracks over 1,000 surviving sundials on religious buildings.

This Christian practice has its roots further back in Classical Antiquity. In Roman times, the forums of Roman cities would ring bells in intervals of three hours from 6am to 6pm, and the common urban dwellers would have been able to keep time by listening.

The situation is similar in the Far East. Chinese local governments (and military commands) employed services to notify residents of the time throughout the night. They would typically beating drums on a two-hour interval between 7pm and 5am. The timings were determined by specialists watching hourglasses, as well as burning incenses or candles. During day time, most people also got by looking at the sky or a sundial.

You are correct to point out that celestial movements change throughout the year. However, seasonal variations matters very little when you only count time in hours, rather than minutes or even quarters of hours. Even the concept of equal hours itself only reached Europe by in the Late Middle Ages, but from then on sundials started having different hours for different seasons.