Using your Citizen Eco-Drive CA4500-91X Chronograph is a breeze. To set the time and date, use the buttons on the side of the watch. You can switch between 12 and 24-hour time according to your preference. The chronograph function lets you time events up to 60 minutes with 1/5 second precision - just press the relevant buttons to start, stop, and reset. Since it's water resistant up to 100 meters, you can wear it while swimming or in light rain, but avoid high-pressure water activities like diving. Keep it in a well-lit place to maintain the power reserve. If the low charge indicator shows, expose it to sunlight or bright artificial light. Clean the watch regularly with a soft, dry cloth. Avoid exposing it to harsh chemicals or extreme temperatures. When not in use, store it in a watch box to prevent scratches.