ISO 19235:2015 specifies the basic parameters, requirements, and testing methods of timing accuracy for analogue quartz clocks, hereinafter referred to as "the quartz clock".

This International Standard applies to analogue quartz table and wall clocks which the oscillator frequency is 32 768 Hz and the nominal voltage is DC 1,5 V. Analogue quartz clock movements can refer to it.

This International Standard does not apply to the following quartz clocks:

- clocks for particular applications such as clocks used in aircraft, ship, vehicle, and facilities;

- clocks incorporated into other products;

- clocks in which time is radio-synchronized.