Keep the clock near a window facing the direction of your local atomic transmitter during this time.

: If the clock becomes unresponsive, remove the battery, wait 1 minute , and then reinsert it to perform a full system reset.

Press and hold the button (Force Receive) for 3 seconds. All hands will return to the 12:00 position.

Here is a deep dive into mastering your CH-899 radio-controlled clock, covering everything from initial setup to manual overrides. The "Zen" Setup (Automatic)