In an electronic watch, the component corresponding to pendulum of a pendulum clock is a

The pendulum in a pendulum clock is the device that provides a stable, periodic oscillation used to mark equal time intervals. In modern electronic watches this role is fulfilled by a quartz crystal that vibrates at a very stable resonant frequency; the crystal’s rapid, periodic vibrations act as the timebase for counting seconds and driving the display [1]. Quartz clocks and watches therefore use a crystal-controlled electronic oscillator as their timekeeping element, unlike transistors or diodes which are supporting electronic components, or a balance wheel which is the mechanical equivalent in non-quartz (mechanical or early electric) watches [2]. Hence the crystal oscillator corresponds to the pendulum’s function. [2]

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > THINK LIKE A SCIENTIST! > p. 111
2. [2] https://en.wikipedia.org/wiki/Quartz_clock