A chronograph is a watch with an additional stopwatch function. It's operated using the pushers on the case.
Generally, it works like this:
- Use the top pusher to start timing.
- Use the top pusher to stop timing again.
- Use the bottom pusher to reset the chronograph hands to zero.
Please only reset the chronograph once timing has been stopped. Never restart the chronograph during a reset.
The exact function of the sub-dials can vary depending on the model. If you're unsure, please check your watch's instruction manual.