Why are synchronous motors used for electric clocks and timers?

Synchronous motors are used for electric clocks and timers because they operate at a constant speed that is directly proportional to the frequency of the alternating current power supply.12

Because the motor runs in step with this frequency, it provides a reliable and consistent rate of rotation when coupled with reduction gearing to drive clock hands or timing mechanisms. In these applications, the motor's ability to maintain a constant speed is crucial for accurate timekeeping. While the motor itself does not possess inherent timekeeping properties, its performance is highly dependent on the frequency stability of the electrical grid. Additionally, specialized versions such as the hysteresis motor are often utilized in these devices because they are quiet and provide good starting torque.213