The Casio HDC-600 is a series of watches. While there are many different sub-models, they are all basically the same. The Casio watch module number for the HDC-600 series is 2747. The HDC-600 series contains an analogue and a digital clock. The procedure to set the analogue clock is different than the procedure to set the digital clock. If your analogue clock shows the time incorrectly, you can fix it in a matter of minutes.
Locate the "C" button on your Casio HDC-600 watch. The "C" button is the button in the bottom-left corner of the watch (when you are facing the screen).
Press the "C" button six times to access the analogue-time programming mode. Locate button "A," which is the button in the upper-left corner, and then press and hold it until the digital screen flashes. When the digital screen flashes, the analogue clock is ready for programming.
Press button "D," which is the button in the bottom-right corner, to advance the analogue time by 20 seconds. Each time you push the button, the time advances 20 seconds. If you want to adjust the time more quickly, press and hold "D" for rapid advancement. If you need to adjust the time by several hours, consider using extreme rapid advancement. Use extreme rapid advancement by pressing and hold "D" and "B."
Release or stop pressing "D" when the correct time shows on the analogue clock. Press "A" then "C" to exit the programming mode.