Answer: Before you remove the original head unit, make sure the original radio is set to „automatic“ instead of „manual“ in the time settings menu. If it is still set to „automatic“ you will not be able to set the time of the board computer anymore, as it is relying on the transmission of time data through the original radio. The ZE-NC3810 does not support that function. Depending on vehicle configuration it might not be possible to change from „automatic“ to „manual“ after radio swapping. You will most likely be forced to reinstall the original radio, for the sole purpose of setting the time, if you omit this step.