Before the advent of the mechanical clock, different time indication were used. The position of the shadow, the height of the remaining candle, the water level — most often the time indication depended on the clock device. The first mechanical watches, which appeared in the 14th century, had diverse time indication. In addition to the arrows was used rings, labels on disks, sculptural figures.
In 1577, Jost Burgi invented the minute hand, but it became standard in hours only at the end of the 17th century. Since then, the development of the time indication has stopped before the appearance of a electronic clock with a symbols. Wristwatches are lucky a little more: retrogrades, jumping hours, etc. Experiments continue to this day. But the wall clock remained with the same time indication as their distant ancestors.