The Casio G-Shock watch is an atomic watch that automatically receives a time signal from atomic clocks worldwide on a regular basis, meaning the watch always displays an accurate time and does not need to be set manually. The watch is waterproof and shock-resistant, and can be purchased online or in many authorized retail stores. Setting the time on the Casio G-Shock watch is relatively simple and only requires a few steps.

Place the G-Shock watch in direct sunlight to provide solar power to the watch mechanisms prior to setting it. The watch does not need a battery to operate, but should be kept in sunlight as much as possible to provide solar energy power. Wear the watch on an uncovered wrist when possible to provide power to the watch.

Press down the top button on the left-hand side of the watch until the city code on the left-hand side of the display flashes to begin setting the time. Press the bottom button on the right-hand side of the watch until the desired home city code appears on the watch display. If your home city is not displayed, choose the nearest geographical city location.

Perform a manual time reception by setting the watch on a stable surface near a window with the 12:00 pointing towards the window. Hold down the bottom button on the right-hand side of the watch for a few seconds until the time signal flashes on the display. Wait 2 to 7 minutes for the signal reception to complete. The reception date and time will appear on the display when the time signal reception is complete.

Set the alarm time by pressing the bottom button on the left-hand side of the watch until the alarm is displayed. Press the bottom button on the right-hand side of the watch to enter the alarm mode, and then hold down the top button on the left-hand side of the watch until the desired time is reached. Press the button on the bottom left-hand side of the watch to move to the minutes display. Press the top button on the left-hand side of the watch to confirm the alarm time.