This seems a stupid question. Even with our choices of dials, digital or talking, we know what they are. But mechanical time keeping began as alarm clocks, to wake priests for their services, or to announce services through the day, or for people to take lunch breaks. Sometimes the alarm would disturb a human who would then go and ring a larger bell to make the announcement of the time public, which is where the quarter jacks on clocks probably originate. Bells were rung for the opening of town gates, for the opening and closing of markets, there were passing bells to warn that a person was dying, bells for celebrations, for deaths, for storms approaching or invasion. Large towns and cities became so chaotic auditorily that clocks telling the time with a dial became more common. So time keeping began to move from auditory to visual. But it also became more complicated, as even the most ignorant would have some way of counting chimes, whereas reading from a clock face on the town gate or church tower took a degree of learning.
But the clock face itself came in many forms. Some ran anticlockwise, in the divisions and numbers of numbers shown, the start of counting – did it start from dawn, from midday, how many hands, and whether they were all on the same dial. All these varied for many years.