A digital watch uses a quartz crystal oscillator to keep track of time. The crystal oscillates at a consistent frequency when an electrical current is passed through it. The watch then counts the number of oscillations to accurately measure time.
A digital watch has a microchip that stores and executes instructions to display different features and modes. The microchip receives input from the buttons on the watch and displays the corresponding information on the screen.
Most digital watches have a small battery-powered chip called a CMOS (complementary metal-oxide-semiconductor) that stores the date and time information. This chip uses very little power and allows the watch to retain the information even when the main battery is changed.
Some digital watches have a built-in feature that automatically adjusts for daylight saving time. Others require manual adjustment by the user. This is done by changing the time zone setting on the watch.
The microchip in a digital watch has a memory bank where it can store different settings and alarms. When the user sets an alarm or timer, the microchip activates the corresponding feature and displays the information on the screen at the designated time.