JJY Simulator is a utility app for iPhone that allows you to synchronize your device with the radio clocks available in Japan. It generates a simulated signal that mimics the standard radio waves used by the JJY (Japan Standard Time) transmitter, outputting it as a 13.3kHz audio signal and using a 3x harmonic (40kHz) to adjust the time.

To use JJY Simulator, simply connect your headphones to the iPhone's headphone jack and place the device near the radio clock.

Next, set the volume to maximum and enable the "Output Audio Signal" option in the app.

Put the radio clock in forced reception mode and wait for a few minutes until the time is synchronized.

With JJY Simulator, you can easily ensure that your iPhone's time is accurate and aligned with the official time in Japan.