Hi,
Try the following and see if it helps.
1. Remove the AC cord from the wall outlet.
2. Remove the battery from the clock/radio.
3. Press and hold the Time Zone button for approximately 15 seconds then release.
4. Connect the AC cord to the wall outlet and turn on.
5. Insert the battery back into the battery compartment. (ensure that the +ve mark on the battery is facing up)
6. Press the Radio button to remove the low battery symbol being displayed.
Hopefully you now can set the time etc.