If you cannot download clocking data over the network (Error -8) please check that your network connection is working.
If you have a C250 Wifi clock check that the terminal has connection to the Wifi. A Reboot may be required.
To check if the clock is connected to wifi, there will be a little W at the top of the clock interface. If the W is green, the terminal is connected to wifi (although may not have the correct IP). If the W is grey, the clock does not have the correct wifi details, or none input.